So you know DH's relationship with FIL is kind of complicated. Last night, he said that his dad has been asking us to come for Thanksgiving or Christmas, and that SIL "might" be there with her kids, Norman Rockwell, etc. DH is conflicted. He is cheap, so he hates airfare x 4. (I priced Thanksgiving flights just for kicks, and it's about $1600 for the four of us. But I can probably fly on miles, which would reduce that, and Wooz may or may not have enough miles that we could buy her up to a ticket.) Neither of us want to do 11 hours in the car with the kids. We talked about splitting it up over two days, but then that's two days going, two days coming back, and we're already at four days and we haven't even seen anyone yet.
So there are no easy, obvious answers here. But I have seen this before, and I'm afraid that DH will hem and haw for weeks and weeks, and then suddenly airfare will be more like $2000 and all that will be left are 5:00 a.m. and 9:00 p.m. flights. And then he'll be bitching about that, and his dad will be guilting him about missing Thanksgiving, his sister will post 400 Instagram pics of her with FIL and the kids, and DH will go into a major funk and spend Thanksgiving weekend pouting.
What he really needs to do is make up his mind and commit to whatever that is, but I know from experience that it's not his strength. He's more of a long-term ruminator. Which I could live with, if he would STFU about the consequences. But he doesn't. Ugh.
As an aside, SIL is fun but also the flakiest person I've ever met, so saying she "might" be there doesn't mean jack, IME. It would be nice to see her and the kids, but I wouldn't make it a major factor in our decision because you just never know if she'll show up.
If it were up to me, I'd buy the Thanksgiving tickets and call it a day. But I would not be at all sad if we did Thanksgiving at home with my mom and the kids. We just need to figure it out before November 12 or something.