We arrive in Tampa on Friday, December 27th at 3:25pm. I would hope to be on the road by 4:30pm after getting luggage and rental car. How bad will to traffice be getting from the airport to I4 and then to Kissimmee?
I wouldn't expect it to be that bad. The traffic that week is going to be pretty light because a lot of people are off. The actual drive should take you about 75 minutes.