I am going to make this seitan recipe http://www.theppk.com/2011/11/seitan-ro ... and-leeks/
I don't need to freeze it, but it does freeze wonderfully according to the directions.
Some soups are pretty thanksgivingy (is that a word? it is now). Like a nice butternut squash soup, or a sweet potato bisque. And don't forget, there are a TON of great pumpkin soups out there. They would all freeze well. Make a ton, and it will be a great first course!
Why not make the very supermarket friendly stuff when you get there? Like mashed potatoes, roasted veggies. Those are easy to find ingredients for, and also to make. You can make gravy before and freeze it!
Pie does not freeze well, but it travels pretty well. Just wrap in foil and you are good for a day or so.