Min mooch, so sorry for your loss. I don't know if you do t he traditional. (Irish at least) Christmas candle in the window to show there is. "Room at the inn". But this could be a year to start it. We always have the youngest light it, and have always used it as a chance to reflect on all the good and bad things that have happened in the year. We also tend to remember those who aren't here to celebrate Christmas with us this year, including grandparents who died a few years ago now, but also having a Few happy memories of them too. This year will probably be very very hard to look at the nice side, but it may give you something that you can over time move more into reflection rather than pain as Christmases go past. (I may be putting it very badly, and don't mean to hurt you more or cause upset, but I thought you might like it).
Celestial, in terms of having a smaller family Christmas, what do your family want? Does it give you a chance to ditch Granny's beloved red cabbage and have nice easy peas instead, for example? Does everyone want turkey, and normally eat it at Christmas even if not any other time? Do some of the DCs want a chance to do part of the meal themselves - starter, veg, deserts, or even turkey itself? Or take charge of a lovely festive breakfasts?
Do you normally get a chance for a walk, or family board game after dinner, or watching a nice DVD together, or having a cheesy sing'-song? Would you LIKE a chance to do that? Or get a really tricky jigsaw that everyone can help work on for a few days?
Get the older DCs to help out the day before with prep, emptying bins, peeling veg, younger could fetch and carry or set the table. But also have a few fun things if everyone pitches in. And if all prepped it means you have the time to relax and enjoy the next day.
We are only 3, but always have to either go to Mil and DMs houses for turkey dinners at lunch and dinner, when we are down home, or visit gloats of wider family relations when we stay home. A day of just up, stockings, breakfast, church, and relaxing in front of the fire with a nice meal needing the odd eye cast over it would be bliss , and allow dd time to play with her toys in peace.