The current estimate are for 50% without power in the Orange/Osceola areas. Overall they expect 2.5 million locations w/out power. Major substations and delivery lines will certainly fail during this storm. Recovery will take sometime; honestly, I'll be surprised of WDW is up and running Tuesday; They will be severely short staffed; just clean up alone will be a major undertaking; not to mention i'm sure their own staff may not be able to get to work or have any utilities at their own home. Now the storm does seem to be going more west which may change the winds a bit. but 80-110 mph sustained winds for hours is going make a mess of the area.
The storm weakened because of eye-wall replacement that happens in hurricanes, it gain strength again, however some of the mountains in Cuba may help rip some of it up.
If I had to guess, expect WDW closed late Sat through Monday. Tuesday right now is a crapshoot, depending on the severity of the storm.