We went last Christmas from the 11th Dec, to the 5th Jan. We found the first week the parks crowd levels were managable, however during the week of Christmas is was very very very busy. We hardly did anything! We still had a great time, made use of Fast passes etc. Over the new year we moved to the Dolphin to be near Epcot/MGM. On NYE it was wall to wall people in Epcot. We saw the first fireworks, but it took us a long time to walk any where. Unfortunatly our DD4 became very ill and we had to leave early. It was a very close call as 5 mins coming off soaring she threw up !! That would have been a nice present for the rest of the riders! She was ill for the rest of the holiday. Because of this, one thing we discovered and would def. do again, is watch the NY fireworks from the bridge nearest Dolphin. There was about 20/30 people there and you saw all of Epcots, MGM's and DDD's/PI fireworks. It was amazing, poor DH didn't get to see them as he took DD4 back to the room. I would give the parks a miss on that night and eat in the boardwalk and watch the amazing display from the bridge.