I don't see much need to avoid Christmas. It's really an old pagan holiday, celebrating the winter solstice, that the Church took over and adapted for its purposes (a very common move for the Catholic Church, by the way). No one who looked into the matter thinks Jesus was actually born at the end of December and I think it's viable to accent the "holiday" aspects (the tree, the lights, etc.) and downplay the religious aspects (the Advent, the Nativity displays, etc.)