We were originally going to go to Oregon this year for Thanksgiving, as we did with that little short getaway in July. The idea being that we're trying to be pretty safe down here in SoCal, and my wife's mom and stepdad up there are being pretty safe, so if we hang out together it's still mostly safe and shouldn't cause spread (or if it does, it's VERY limited because there were only four of us in the household for those 4.5 days).
We decided not to go because we knew there would be a 20+ person Thanksgiving gathering. If they had restricted it only to us, them, and my brother-in-law's family (who are mostly isolating too, living out in the country), I think it would be mostly safe. But once they all got roped into the traditional big event, it became a big-time no. And we were proven right; they moved it to my brother-in-law's house, but my mother-in-law is still getting roped into not only cooking for everyone but they're going to be there, so out of guilt they're taking a significant risk.
I think that's a lot of it this year. People don't want to anger their families by taking a year off from the tradition, so even those people who don't want to be a part of it will end up being a part of it to avoid rocking the boat.