Okay, how wedded are you to Turkey? Because if not that wedded, here is my suggestion, tried and tested over years of hosting christmas dinner with limited space, a few challenges etc.
Rib of beef as the main. I do this because it is quite forgiving. It also benefits from hilariously long resting times, so it doesn't matter if everything else is goign a bit sideways. And you can take it out and then use the oven for other things. And, with a big piece for a large crowd, you can easily get more well cooked and some less cooked pieces. For 10 people at Christmas, I would get a large one with 3 ribs.
Potatoes - I will never understand the English obsession with different types of potato. A large massive pile of roasties are just fine. do not use duck fat, so that your veggies can also eat them. You do not need additional potato. If you really really want to go that route, go with a potato dauphinoise.
For myself, I prefer to go creamy in the form of a cauliflower cheese. This has the added benefit that I can make this the day before (but not bake it), then just put it in the oven when I take the beef out.
Yorkshire pudding.
Now, this is where it gets complicated. If you want lots of traditional veg, red cabbage and brussel sprouts are fine. You can do these on the stove top. The cabbage in particular can probalby be cooked earlier and then warmed through while you're cooking gravy. I tend to have all my stove top veggies prepped and in pots in water on the stove, ready to be turned on when I want them.
Then, for the veggie, go for a lovely tart. This can be shop bought or it can be home made. Again, you can make it mostly the day before, then cook it while the meat is resting. I did butternut and goats cheese last time. Went down brilliantly.
For starters, I usually do a mix of pates but I usually buy in a mushroom pate. That won't work for you so I'd see what other veggie terrine/pate options are out there.