To be honest, the Christmas markets thing is better in northern Europe.

As for me, next year I'm going to Italy for December, and I'm carving out a week or more to stay in an airbnb with a kitchenette, and then I'm just going to spend the whole week eating (and cooking the fresh pastas and prepared sauces) in Bologna, Parma, and Modena. I've over the buying chachkas thing.

If I were in the south or even in Rome, I would go to Matera for the living nativity scenes.