I have driven quite a few times from Bridgeport CT.
It has taken me as little as 15 hours and as much as 20 hours depending on the traffic. I don't speed excessivly, I set my cruise control 5 miles over the posted speed limit and I have never gotten stopped.
I leave CT around 6 or 7 pm so I miss the NY and Washington traffic. After that there is not as much traffic. The one thing different about driving down south compared to up north is that there is a greater distance between exits down south so less people use the highway. We up north tend to use I-95 as a regular road to get from one place to another quicker. Of course we also have more accidents and traffic because of this reason.
I drive non-stop, except for gas and bathroom breaks. I try to pack sandwiches and soda but sometime I don't get to it and need to stop and get something to eat.
Of course I should tell you that I am a nurse and used to work nights. I am used to going through the night without sleep and having children sometimes I had to do without the sleep days too.
If I leave at 7 pm I can be at the parks at around noon and start my day at Epcot. Who needs sleep, you can do that at home. Peggie