You could also try going to visit one group in the morning and another in the evening. I know that's a lot of work, but you would get to see two parts of your family, and not just one. Or plan a "second" thanksgiving the next day. With my family on like Christmas, we spend Christmas eve with friends and Christmas day with family.

that is almost what we are doing. locally we are seeing one side early in the day, and then later in the day driving 4 hours to the other side of the family and spending a few days with them. lots of driving but everyone is happy...or happier.

It seems like a lot of driving but hopefully it'll turn out well. Enjoy your Thanksgiving!