I don't think I have ever thought of Thanksgiving as a "formal" dinner. We always have so much fun and laughter at our family gatherings. When the stories start, there is no stopping us.
Why did I suggest mac and cheese? The little kids can be very picky eaters. Parents will load up their plates with foods they are not fed every day. Whoever is making the big meal in our family, lets the cook know what her favorite veggie is. This year I chose petite peas. The last time I made the dinner, my SIL chose creamed carrots. How many little kids do you know would honestly eat Brussels Sprouts? Or even carrots. When was the last time you put stuffing on your child's plate? So now the meal has become a battle with the kids. Take a good look at the additions we put into the stuffing. Raisins, apples, walnuts, dates, oysters, etc. How many of those foods are every day foods for the kids? You put that on their plate and their reaction is stunning. They push it to the side and if it touches any of the other foods on their plate, they won't touch them either.