I used to find hours at the stove very tedious so developed my own way of preparing the main Christmas Dinner around 25 years ago. It starts on Christmas Eve and I do one veggie at a time 'as the spirit moves'. I usually start with a big pot of potatoes and take a load out half way through for roasting, then mash the rest. The mash then go into an oven-proof, round tray (which fits in the fridge). I put the mash on the tray as if it were a slice of cake, cover in tinfoil then pop it into the fridge, followed by washing up the tatoe pot. The roasties go into a separate (tinfoil) tray in the fridge.
As the day progresses, I'll then do maybe the carrots, later the pigs in blankets, swede, etc etc, as and when I feel like it. Individually, they get added to the tray in the fridge (when cooled) in the form of another 'cake slice'. On Christmas Day, the whole tray is wrapped in tinfoil and popped into the oven for 25 mins and I have all the veggies on one tray, piping hot and with no veggie pot washing up. This only leaves the turkey, the gravy and roasties to be done on the day.
Works for me 
This way, I'm no longer slave to the kitchen at Christmas and everything is lovely and hot on the day. Provided the tray is loosely sealed with the tinfoil, nothing over cooks.