If you know you want to go, no reason to wait and risk not getting in. It is unlikely there will be any discounts offered at that time so just make your ressie now, it only requires a small deposit and you can always cancel.
We just got a "bounce back" "E" mail for a discount that included the cabins (not campsites) only good 12/17-12/24 whereas the discount is offered for the resorts 11/28-12/24. I wouldn't wait too long.