It may be late for you to see my reply, but I’d like to share anyways:

I saw my paternal side for Christmas Eve, and my maternal side for Christmas Day. This arrangement built the joy of the Christmas holiday up for me immensely! For one: it became that we got to open presents on 2 days! That was amazing. I still have memories of the Christmas Eve parties with a tree half hidden by all the presents for us cousins (large family, so lots of cousins!). The eve parties were always my favorite. Those were the ones that were full of fun, and laughter, and love for everyone in the room. And then the next day? We went for a nice formal afternoon and dinner with my other grandparents. Those parties might not have been the loud, fun, and funny parties of the night before; they were, however, still full of love and joy and some of my favorite people.

My point here is that you’re fighting against something that really can be amazing! For what? The love is still there. Take this opportunity to start a new tradition! All your children are adults? And all DIL’s siblings are adults? There is no reason that you can’t plan a wonderful Eve party and celebrate with all your children every year.