If you drive and have a few $$$ for extras, you can't go wrong with (1) Blizzard Beach; (2) Cirque du Soleil - which I'd have as #1, but feel the kids would rank as #2.
OR try one of the other parks - IOA, for example, absolutely thrilled the kids!
We drive from eastern Canada - more than 2000 miles - and can guarantee that at least from our hometown, it is far cheaper to do this and spend the extra $$ on motels on the road, than to fly. The cheapest rate we could obtain in December would have seen us paying almost $2,000 for airfare for our family. That pays for a lot of gas, motel rooms and food.... (And we are fortunate to have enough holidays to do this and a willing DH driver!).