Well, there are no references to Christianity or to Jesus in the film or the book. And Christians only even started celebrating Christmas around the fourth century A.D.. Before that, the holiday was a winter harvest festival in many pagan cultures, not to mention the Roman holiday of Saturnalia. But, still, it wasn’t much of a celebrated holiday associated with Christianity until the 18th or 19th centuries.
That’s for Santa? Well that legend has been going on for about as long as Christmas has been, but didn’t really get associated with it much until the early 19th century.
So, there was no who Jesus. But, it’s worth noting, they probably had a Christmas Krampus.