Thanks everyone for all the great suggestions for keeping myself busy while we're there. My problem is that I can no longer contain the snark. I used to be able to bite my tongue, just go along for the visit. MIL showed her true colors and we had a huge blow-up. I don't have much to do with her, say Hi when she facetimes with DH/DS or they visited here, and those visits are much easier. When we go there, SIL is thrown into the mix, and everything is just much more difficult. We're only visiting because I insisted so DH could see them (he has no vacation time left), and now I'm regretting suggesting it, as I have to deal with them on their home turf.
I can understand suggesting finding the good. I've accepted that I don't like them and they don't like me. MIL is racist and narrow minded, and as I'm a foreigner (as she's reminded me), everything I do is "strange". Putting tomatoes on my grilled cheese sandwich was met with disdain and derision
I'm not going to try to get them to like me anymore, and I don't have to like them. I just have to be polite/civil for 5 days, then I get to leave. Since I've stepped back and defer all IL related issues to DH, it's been much less stressful for me. DH hasn't been so happy about it as he now gets all the emails/phone calls, but it's his family drama.