We ended up in just this situation last September. We had a vacation all planned to go to the FL Keys but Hurricane Ike was coming through.
So, FOUR days before we were scheduled to leave, we switched it all up and went to WDW! US Airways allowed us to ditch our South Florida flights because of the hurricane and gave us full credit for the $ we'd paid. We tried many flight combos and ended up flying into Jacksonville and driving down. We flew back out of Orlando.
When this all started looming about 6 days before we left, I called
AAA to check on packages and any savings, but the agents really balked and said they couldn't do it on such short notice, saying they couldn't even get all the documents shipped in time. So I ended up doing it direct through Disney.
By the time we booked, there were no Value resorts left, so we ended up at CBR (we could also have stayed at the Dolphin for similar price but I didn't understand how that all worked). I'm sure we could have gotten a slightly better deal for tickets, but again, we couldn't get anything mailed out because it was so close.
We had to take our trip that particular week because we had the babysitter arranged and our business was having renovation work done then. We had no ADRs and couldn't find any place to do an on-the-spot walk-in. I read the UOG on the plane. We still had a great time, but it's not how I would recommend doing it.
PHXscuba
p.s. For a total OCD trip planner like me (on her first visit to WDW in 20 years) this was very stressful. But I did learn I could have a great time without months of research!