OP here. I went. I was afraid that my in-laws would think that I created an excuse. Coming here is a huge mistake. It took me two hours to extricate myself from the family and I would have been far more productive at home.
I guess I forgot (or toned down) how truly important xmas is to my in-laws, and they wanted a full play-by-play recitation of xmas eve, x-mas day, all of the presents, etc. Ugh. Alas. Tomorrow my DH will take our kids out to play and I'll probably have the house to myself or I can go to the library.