I don't think there any place in the Keys that is more then 2 feet above sea level! Water came over US1 (the only road in/out) in Key Largo during Katrina's Cat 1 landfall, at Cat 3 coming from the SW will be much, much worst due to the shallowness of Florida Bay and the increase winds - plus you got to factor in Wilma's forward speed... all in all this not going to be pretty in southern FL.

High tide in Key West is 1:35AM (EDT 10/24) - which will be just slightly ahead of when the eye passes close to them. For tides in other places go here: http://66.135.8.10/tideserver/LocationSelect.asp pick FL as the state, pick the date and then scroll down. Tides are listed from north to south for the east (Atlantic) side till you hit Key West. Then tides pickup at Flamingo (Florida Bay) and are listed from south to north up the west (Gulf) side of the state. Marco Island will have high tide around 4:30AM, with landfall estimated to be around 6-8AM the surge will be very high I fear. I do alot of fishing in Florida Bay and the tides are much wind driven given the shallow water.