FWIW, we were in WDW during Irma. The day before Irma hit, everyone else had apparently abandoned FL, because we hit all four parks and rode most of the headliner attractions with almost no wait. I have a photo of TSMM (remember, this was before Toy Story Land had opened) with a 5 minute standby wait on the sign. The Citizens of Hollywood in DHS were doing some awesome pre-hurricane preparation shows, although the wind made it hard to hear them well.
Irma came through overnight and we were forced to stay in the hotel much of the next day. We were at Wilderness Lodge, so it wasn't that bad. The Country Bears and Brer Bear were entertaining guests in the lobby. The menu at Whispering Canyon was reduced in options, but they also reduced the prices. And, I have video of Big Al and Shaker bringing ketchup to our table!
When they opened the parks on 9/12, they honored our MNSSHP tickets that we couldn't use on the night before Irma. The crowds were again really low and it was easy to get a lot done, although we only went to MK that day.
My kids said we should plan all of our WDW trips during a hurricane. And I gotta say, it was one of the most fun trips we've had.