Hi mate, I have been there around the same time and I don't recall how busy it was. Generally less Aussies/Westerners during Christmas, maybe more locals.
As far as snow, there will be more than enough for a good time. As to whether you will get any descent dumps is a crap shoot. Sometimes December goes off it's nut, other times it can be slow and a bit drizzly on occassion.
Well thats my observations anyway.:)