Modern-day version of A Christmas Carol
I love this movie! Watching it again recently I noticed how this is a version of "A Christmas Carol."
The family except for Max and Omi are Scrooge. Omi is Marley because she warns the family if they don't change, they will be haunted, and they don't believe her at first just like Scrooge. Krampus' minions represent the 3 ghosts. And just like the end of A Christmas Carol it ends with being thrown into a pit of fire but then waking up in your own bed and it may or may not have been a dream. The fact that the first spoken lines are from a TV playing "A Christmas Carol," gives further credibility to this.