Hi and welcome!!!
I've never been there at Christmas. For me, Christmas is about being home with my siblings and mom. We're both teachers, so for us, trips always happen over the summer. We're now planning for summer 2014.
Christmas week, though I'm sure it's amazing, IS one of the 2 most crowded times of year (second only to Easter week.) And prices tend to be higher, with fewer (to no) discounts offered. So if you haven't said anything to the kids yet, perhaps you might want to consider next summer instead? It would give you more time to save, as well as enabling you to go over "value season" when things are a bit cheaper.