I would wait too. We took a 12 hr road trip to see family a month after child #3. He was an easy delivery, pretty easy baby & I'd figured, eh, I've done the baby thing, traveling w/#3 so small won't be much of an issue.
It was completely miserable. He wasn't on a schedule yet so I was always nursing & it wasn't quite comfortable enough to be in the room w/that part of the family. Plus leaky, post partum, emotional & trying to take care of the older two w/DH. I spent most of the trip either nursing or napping alone in our basement room w/the baby. The ride was horrific and my older ones did not behave that part of the trip either. Despite the excitement of Disney, the heat plus such a young baby would be a very tough trip.