Just in case anyone was wondering, lol. We made the decision to go to the party on 12/20. It was a little drizzly, but over all not to bad. Only downfall to the rain was that they did not have snow on Main St. that night.
We got there about 3pm (DVC members) and were able to enter before the huge crowd that was lined up already. We went to the right as we entered and down the "party path" but I now wish we wouldn't have done that because we only made it back to Main St. one other time that evening and I felt like I missed "all the feels" of walking up Main St. Anyway, when we went to purchase the tickets, the Castmember helping us told us we made a good choice as he had just helped more than 5 guests switch their tickets from 12/20 to 12/21. He said there hadn't been sold out on Friday until about an hour before I asked. He was right. The crowds for this particular party were very low. We rode every single ride we wanted, including 7DMT, PP and Jingle Cruise with minimal waits. We also saw multiple characters. All in all it was a good night!