When I was a kid, a drunk taxi driver killed someone important in our family on December 17. The sudden unexpected death meant Christmas was basically over--not just that year, every year after. Every year after that, our family tended to run away during Christmas--usually we would up and travel to somewhere warm. The tree went up and we'd go through the motions, but I think that was for the little kids. The adults had lost the joy, and by gum, they need the joy and connectedness too.
Not that anyone asked, but I say when someone dies suddenly, tragically, close to a major holiday, don't even bother pretending to celebrate after that. The holiday is done, toast, finished as a time of joy at least for a few years. Run away. Pick another time, in the spring maybe, for the wholesome good family get-togethers, for rebirth celebration, and season of generosity. The kids might not like it, but they're more resilient than the grown-ups.
(Although soldiering through and pretending you're not filled with glum despair has its reasonable advocates too)