I-4 has a very nasty reputation. It is busy at all points in the day, but is absolutely impossible from 4-8pm on Monday through Friday. I drive from University of Central Florida to Disney, and by Orlando is always a mess to get through. With you being a CP, i'd imagine you would be closer. But anywhere near Disney/Universal/Outlets gets pretty packed too. Factor in any kind of accident on the side of the road and you have an instant parking lot.
Numbers game. In the last 4 days, I have been stuck in unmoving traffic on I-4 3 times. Cars, buses and vans seem to be catching on fire a lot lately is all I have to say...
There are alternate ways. Like for MK, there is Reams Road. Sure, it's longer and one lane. But as long as people keep moving that's all you need.