Make the best of it

Whether you love them or hate them, it's the holidays and your in-laws are here to stay. Even if you adore them, it's still possible they'll get on your nerves while being in close quarters. And if you hate them, well, it doesn't have to be (totally) miserable for the whole visit. Yes, really. Here's a laundry list of tips on how to make it through the visit with your sanity and family still intact.
Be diplomatic

No matter how much your partner's parents may get under your skin during the holidays, you're not going to change the habits of their family by complaining or treating them poorly. Try to have compassion and extra patience with your in-laws the same way you do with your kids while they're mid-meltdown. Let your partner do the heavy lifting when it comes to resolving conflicts with their parents.
Buddy up

Institute a buddy system with your spouse. Know the subtle signs that show they're nearing the end of their patience with your parents or theirs, and bail each other out as necessary. Make up excuses to run to the store for diapers, go for a walk or whatever feasible thing you can think of to get one or both of you out of the situation to cool off.
Make plans outside the house

Plan a fun family outing for the kids with your in-laws in tow. It's hard for anyone to misbehave when you're focused on having a good time with the kids. Even better, let your in-laws take the lead with the kids and take some candid photos of them that you can print, frame and send them home with as a gift.
Go to bed early

By the end of the day, even people you love can seem annoying. Rather than stay up because your father-in-law likes to watch "Law & Order" reruns until way after the kids are in bed, say goodnight, excuse yourself and turn in early. Make a habit of it starting with the first night and you can do it for the entire visit without seeming rude. Blame the kids for tiring you out, if you need an excuse. Going to bed early might also give your partner some alone time with their parents—which they'll appreciate—and you get quiet time on top of it. Win-win.
Set up a surprise activity

If your in-laws are visiting from out of town (or you're visiting them), surprise them with tickets to a museum or reservations at a restaurant they like, so that you can get a few hours apart. It'll be money well spent and your in-laws will thank you for your thoughtful gesture.
Focus on the kids

Kids pick up on stress, so do your best to give them all the snuggles and fun you can manage. As long as your in-laws (or your own parents) are good grandparents, don't cut them off during the holidays. Despite the fact that you might not get along with them, your kids didn't choose for their parents and grandparents not to get along.
Bonding time

If you approach your in-laws' holiday visit as a way for them to bond with your kids, it might take some of the pressure off of you and your partner. Let Grandma and Grandpa participate in bedtime routines, cook breakfast with the kids or whatever else they're comfortable taking on so they can spend quality time together. You can supervise if you really feel it's necessary, but don't hover. Give them some space.
Take care of yourself first

There's no shame in self-care during the holidays (or any time of year). Do what you must to have a pleasant holiday and avoid getting frazzled at all costs. If that means bowing out from cooking and getting catering or letting your mother-in-law take over your kitchen, so be it. Steal little moments away from everyone to enjoy some time with your little ones. Take a long shower to have time to yourself if that's all you can manage. But make sure you take care of yourself.
Sneak some quiet time

If your mother-in-law is a Chatty Kathy and your father-in-law always seems to be putting his foot in his mouth, host a family movie night to keep everyone quiet. If you're lucky, the kids will be entertained, somebody's bound to fall asleep early and nobody will be trying to carry on a conversation. Sneaky, but effective!
Idle hands

Does your mother-in-law crowd you in the kitchen because she always wants to help? Just let her. Give her stuff to chop, slice and dice on a cutting board that's a comfortable distance away from you. She'll feel useful and you'll regain your personal space.
Don't nitpick with your spouse

Being on the same team as your spouse is key during a stressful holiday visit. Pick your battles with the important issues and ignore the smaller ones. It's not worth the fight or stress with your partner when you're already on high alert.
Canned answers for rude questions

If you're constantly being asked when you're going to have the next baby, when you're going to stop breastfeeding or other invasive questions that are really nobody's business but your own, think in advance about what you'll say when these uncomfortable or inappropriate topics come up. Having a canned but polite answer will prevent you from getting flustered and also keep the peace. Make sure your spouse is ready to back you up.
Don't compete with your mother-in-law

See if this scenario sounds familiar: Your mother-in-law practically smothers your husband and the kids while she visits. You know what? Let her. You get them the other 364 days a year. She has fewer opportunities to dote on her son and grandkids, so let her enjoy it and let them enjoy getting loved on. Unless the kids complain about it, it's completely harmless.
Have a safe word

It might sound silly, but come up with a safe word with your partner in advance that signals when you're in distress or need a break from family. Agree together on how to act as a buffer for your spouse when they're fed up, had enough or just need a five-minute breather.
Have realistic expectations

Despite best-laid plans, sometimes no matter how much you try to keep your cool and be graceful, your in-laws won't always keep up their end of the bargain. If you know it's inevitable that your father-in-law is going to bring up politics at the dinner table, arrange to be seated at the kids' table under the guise that you want them to feel included and not separated from all the adults. You'll have a better time without the adult commentary and so will your kids.
Don't fight over family traditions

Your family might do things one way, and your partner's family completely differently—and that's OK. Discuss with your partner in advance if there's something in particular that bothers you, but otherwise just smile, be polite and participate. If your father-in-law insists the entire family go out and cut down a Christmas tree together on the day after Thanksgiving, roll with the punches, even though you don't put your tree up until December. Start your own family traditions, too, so that everyone feels as if they get to do something they like when it comes to the holidays.
Patience is a virtue

Instead of seething silently, speak up about what upsets you if your in-laws overstep boundaries, but give them the benefit of the doubt and try to see the good intentions at the root of annoying behavior. Your in-laws love your family and wouldn't spend the holidays with you if they didn't. They might say or do the wrong thing at times, but it's surely not on purpose.
Just breathe

Even when you adore your in-laws, sometimes they can still get on your nerves. Don't forget to breathe. Most of the time, everyone's just trying to make a memorable experience for the family. Best intentions don't always turn out that way, but try not to get bent out of shape and lose your patience about the small stuff.
They have to leave eventually

If all else fails, focus on the light at the end of the tunnel. Take it day by day, but remember the visit is only temporary and do your best to keep the peace and have patience—even if your mother-in-law's pickiness drives you nuts. But don't lose sight of the fact that you just have to get through a limited number of days together.