We're the same as Ishbel here Down Under - no Thanksgiving, but for Christmas I often do a light seafood starter, then a roast pork leg. Then hubby loves a steamed fruit pudding with hot custard. Really handy on a hot summer's day, with all the trimmings. It's a waste of time and effort as it's just too hot to be cooking it and heats you and the house up too much. But, It would be ideal for a cold winter's day with a simple creamy soup instead of the seafood. Loads of different types of bread with real butter. Only trouble is, you can't move for a few hours after that, and we crash out for a rest with the air-con. and fan on the sofa!
Personally, I'd prefer to do a cold seafood starter, family style (for example, oysters au naturale, cooked then chilled tiger prawns, some scallops in a spicy lemon and parsley dressing) to share with just a light salad and crusty bread.
Then I'd go a pot roast of beef, served simply with the veg from the bottom of the pot, sauce reduced a little and thickened with cornflour. Then something light and icy cold for afters. Like frozen yoghurt with fresh berries. If bony fish is off the menu, try some shark. There are no bones and in my mind the flavour is better than many fish. Just S&P then gentle fry in butter and a bit of oil. Can accompany with a dish of roast veg., tossed in rosemary, cracked black pepper, and thyme.
I know my main is hot, at least the rest is cold. With the pot roast you would get a couple more meals out of it once you add some more fresh cooked veg. Or make it into a pan toasted sanwich with some nice cheese and arugula.