The trip on I-4 would take anywhere from 1 hour 15 minutes to an hour and a half. It is not that long and it helps that you can take the interstate all the way.
drove to Tampa from Kissimmee in 1 hr. took I-4. real easy drive. was a slowdown due to accident but wasn't for long. If going from Orlando add 15 min to your trip depending on what exit you get on the I-4.