I had a "tiny" family compared to a lot of you. (One sister, two cousins....two!) There weren't really any traditions while growing up. I had to be involved at the Christmas play/program at our tiny church all the way through HS since a)We were tiny, and b)My mom was the choir director. Not complaining, that was just the steady thing I had to do every year.
Then I married my husband....he of the 20+ cousins on one side. Needless to say, our first Christmas Eve married we spent at his grandparents, I just sat there a bit wide-eyed with all the people in their basement. Now, all the grandkids are having kids, and I count at least 15 great-grandkids. We will once again spend Christmas Eve at his grandparents this year.
Sounds like heaven and hell all in one place.