I'm late in posting here, and Christmas is over, but I can say a few things about how I spent the time.
Quietly. I put up a tiny artificial tree, and that's about the extent of it this year. When I was younger and had a family, there was a lot more to Christmas even though none of my family are observing Christians.
We've been like this for two or three generations now--observing Christmas as a secular tradition, more like a modified solstice festival.
I was married to a Jewish man who wasn't from an observant home either. Burials were in Jewish cemeteries, memorial services were often at a Jewish temple, a grandfather played pinochle with a local rabbi, and my husband went to a reform temple for religious training as a child. Most of the family observed Christmas as my family and I did--as a holiday and an opportunity to exchange cards and gifts and get together for a special meal. This meal might have been at a deli if it was one with good food. And except for me, at the time there were no non-Jews in the immediate family. Sometimes the Christmas tree was jokingly referred to as a Hanukkah bush.
I don't mean to stir up a controversy that has died down, but just to demonstrate that there are all kinds of people on this board.