We went last year in late Dec and went to MVMCP, but found that the same things are being shown after the last day of the party. In other words, on Dec 20-? they do the same parade, fireworks and snow on Mainstreet without the hard ticket. The only thing you don't have access to is the different characters dressed in Christmas clothes. Also, they sell so many of the tickets, it is very crowded so the wait times are almost as bad as regular park days. I would say skip it if you are going to be there late Dec and get to see the party things without the party price.