I don't want to be the bearer of bad news, but it is possible you wil simply have to take what you can get at this late date. Since NYE reservation have been available for over a month, and with the
DDP, reservations in general have been hard to come by. NYE has, as said, been the single busiest day at WDW, so I would pick a park and try to see what reservation you can get, not planning to leave that park at all during the day. Good luck!!