Hmmm - since those days fall on a weekend, as well as being the holiday, my best guest would be crowded, more crowded and most crowded.
I don't have any suggestions - just be patient!
I tend to stay away from the parks after the 22nd - but the first December we lived here (2003) DD and I went to EPCOT on Christmas Eve Day - fairly early - before noon. I needed to pick up a ticket for my mom's christmas gift. Anyway - it was SOOOO crowded - we got the ticket, maybe stayed in the park 1/2 hour and came home.
We will be in EPCOT on 12/23 this year though - for CP and something I have never done before MK on Christmas Day for breakfast Crystal Palace at 9am! I figure we eat do a couple things and head home when the craziness sets in!
Being local, it is just not worth being in the parks when it is crowded, unless there is a very special event or occasion!
Good luck!