The dungeon should be like lost expedition campaign,except more snow on the ground instead of just ice, and then the minions should be snowmen and reindeer (or small elves). Bosses should be Jack Frost, Evil Santa (Santa with an evil smile and huge wand) and even Rouge Rudolph (don't be hatin the 'deer he needs some love). Drops should be like "Santas coat of the snow,Santas hat of the ice,Evil Wand of Neo-Santa" etc.

Quest rewards "reindeer antlers of the north" or "Rudolphs nose of the cold"

Between now and Christmas I may have more ideas, but don't be shy to say your ideas.