We've gone there the past two Christmas's, arriving a day or two before and staying through the 27th. Yes, the crowds can be bad, and with Rivers of America still closed it takes patience to get through New Orleans Square and Critter Country, but it is an amazing time to go. There are always options to avoid the crowds... hit rides with big capacities like Pirates or Haunted Mansion, and make smart uses of Fast Pass to maximize your ride times. Also attractions like the Enchanted Tiki Room are good places to avoid the crowds. Also for lunch and dinners make reservations as a lot of walk up food establishments are packed.
Sorry for your loss.
Yancy