My family of 5 went last year, and we loved it. We focused on the unique party experiences, like parade, characters, shows, and, of course, "free" cookies and snacks. We also did some of the special rides that were themed for the holidays (Jingle Cruise, Tomorrowland Speedway, Space Mountain, etc).
Full disclosure: we were at a sold out party and we still had an awesome time.
Also, my 5 yo son had an awesome character interaction with Peter Pan where he taught him how to fight pirates and dubbed him an honorary Lost Boy.
It's a great way to get into the Christmas spirit!