I was at Jacksonville Beach when Matthew hit high tide last year. I also know Orlando pretty well. The problem I see is that the storm seems really unpredictable at this point, I think it will be another 48 hours, Wednesday, before we know which side of Florida it will go on. Right now it looks like it could go down the middle of Florida, but it's too early.
If it went down the middle of Florida that would be a real mess for evacuation, as everyone would start to drive north to go to family and friends in other states. My observation about Orlando is that it's inland, so surge and floods are not nearly the issue of coastal cities like Miami or Tampa. And Orlando has a ton of sturdy hotels, malls, airport, etc. Tourist will cancel and go back to their home mostly, so places will be more available to locals. I would just start thinking and talking to people about your housing situation and where they go. Make sure your can food supply is good today, and start consuming all your frozen and refrigerated goods. Make sure you have spate battery packs for mobile phones and such, better to order from places like Amazon today since you have time.