Not very. Its food and wine. If you call right when your window opens, you might find something available, but it will be gone by the end of the day. Make sure to make reservations at home now. Its possible to get completely frozen out of
DVC at that time of year.
Calling now does no good since availablity will start changing ALOT when you get to the seven month window and people start booking their trips starting on their own check in day.