Early December is a very busy period for DVC for a variety of DVC-specific reasons. Other than DVC, however, it's a pretty slow period.
It's a great time to visit WDW -- relatively low crowds, holiday special events and decorations, etc.
Wyndham Bonnet Creek should have plenty of availability and the resort has both 3 and 4 bedroom presidential units. And the location is really hard to beat for convenience to the WDW parks.
If you find a WBC owner, they can check availability for you 13 months out, but they'll have to call to do so. Any Wyndham owner can check availability 10 months out online.