We grew up using an advent calendar that had a bear going from outside to inside the house, from room to room, looking for Christmas and he finally found it on Christmas day.
At Thanksgiving, I overheard my sister-in-law talking about another idea. You use the the advent calendars with the pockets on the bottom. In each pocket you have an activity that you can do as a family or with the kids to celebrate the Christmas season. You can make cookies for a neighbor, read a book on Christmas, watch a Christmas movie, make ornaments, put up the tree, decorate the tree, build a snowman, making paper snowflakes, play a game...
etc.
It sounds like lots of fun. Some of them might need to be moved along the way, because you might not have snow on the day chosen for the snowman, so you can save it for a snowy day! Depending on how many ideas you have, you can do it for the whole month, or make it the 12 days of Christmas! You can also repeat several of the options to lengthen it out.
It sounds like a fun way to spend the Christmas season with the family. By the way, my brother-in-law makes awesome snowflakes. He made one with carolers on the outside, and another with angels. See how creative you can be!