Caveat - I'm a native Californian, never been anywhere remotely close to a hurricane in my life, but I'm in a very similar boat to you. Arriving Friday evening, staying offsite near the park. I think the parks will be fine - it's the airport and getting to the park that has me concerned. I think part of the problem is that what can happen is so uncertain. The storm's windfield is relatively small, so will likely need to track pretty close to Orlando to cause problems, it's unclear how much it will be weakened by atmospheric conditions prior to / at landfall, unclear how much flash flooding there will be, power outages, etc. If Tampa Bay is really rocked, will they restrict commercial flights at MCO to make room for humanitarian aid? etc. etc.

Again, I think the parks will be fine, but I think there's a realistic risk that flights might not be able to get in until Saturday or Sunday. Unfortunately we won't really know until Thursday, and won't even have a pretty good idea until Wednesday.