Another Tampa flight family here-we've done it 3 times, and honestly probably won't do it again without major savings.
Took just over 2 hours from OKW to the airport-that included a potty break for my wife and a Chik Fil A breakfast stop, along with a fill up across the street(Dale Mabry Dr). That was during an early morning rush.
I HATE the Tampa airport now. Signage is poor, both inside and outside of the airport. The rental car garage is nice, but seems like it's miles away.I normally grab the rental car while my wife/kids get the luggage, I then pick them up at the terminal and roll on. It took over an hour to get to the rental facility by tram, get the car, and drive to the terminal.
For one way car rentals, we normally pay in the 60's to/from Tampa for a one day/one way SUV rental. We have flown into Tampa, hit
Walmart for a grocery run, grab a Giordano's Pizza, check in to the resort, then return the car. We have done the same at the Melbourne Airport, although it was a bit longer of a drive.