Wilma definitely did not intensify while over Florida- it maintained its intensity very well as there is a delay between energy cutoff and weakening, and Wilma's time over Florida was well within that delay.

Bottom line is that the total energy in a tropical cyclone cannot increase while over land (provided that it is a purely tropical event). However, I suppose it's possible that the eye of a hurricane could continue to contract if it had been doing so before landfall, and the winds would marginally increase.