The same thing happened to me through the years. My mom always insisted that we go to her house for all holidays. When I finally said "no" one year, she said, "Well, I guess that ends our tradition" and I responded "At some point we have to start our own traditions, and this is the first year". That was hard for her to argue with.
It was also a little easier to do once we had kids, but that shouldn't matter. We'd still go over to her or my in laws for occasional holidays. And everyone was always welcome when we were hosting too, so it wasn't like we shut them out or had hard feelings. We just wanted to get our own thing going.
Good Luck! That situation is awkward, to say the least.