Weird. i tried a Dec4-11 and also shows nothing. I changed the dates to Dec4-7 and got results. Then I changed it to back to Dec4-11 again and got results.
It's probably because the new Fantasyland expansion opens December 6th. Check all the resort catagories. I just checked a couple of the deluxe resorts and they have rooms available. If the resort you want to stay at does not have rooms available, I would call the resort directly and them know you want to change your dates and see if they have something available. Good luck!
I assume you are looking through CRO if they don't have all the dates available then it will not show up as the are completely booked some of the days.