We are from south central PA just by Gettysburg.
Last time we drove, the return trip was 13 1/2 hours just driving time (van kept track and was in pic I took showing roundtrip mileage), plus food stops and bathroom breaks (can't remember total overall time). DH and I (mostly me due to hating DH's driving) take turns.
Best thing that has worked for us (not just on disney trips) is leaving early in the morning and driving straight through. Getting there is always easier than returning. The time and states just seem to fly by.
Magic number seems to be stopping every 2 1/2 to 3 hours for about a 15-20 minute break.
If the ride is longer than 8 hours, we will leave around 3am to get a good portion in while the kids are sleeping. Only takes about 30 mins on the road before ours are back to sleep.
If less than 8 hours we leave around 6 am, kids normally go back to sleep for about an hour or two.
For the return trip, I recommend stopping overnight.
One trip we stayed and went to the parks and left Orlando around 5pm drove till around 11, stopped for the night, and then finished the drive the next day.
Another trip we left Orlando around 830 am and drove straight through. Never again! The last 4 hours was horrible. Everyone was tired and cranky! Seems no one could even look at each other without starting a fight.
Neither DH or I want to try/attempt the leaving around 3am and driving straight through on the return trip. Giving up our last night of park time to get some sleep is not something either of us is willing to give up. And neither one wants to be the 1st one driving with very little sleep. Not worth the potential risks.
We are currently planning a June trip with a friend and her 2 kids (her DH, what a jerk
) who will be on a very strict budget. We will be driving straight through down and doing the overnight stop on the way back. Packing sandwiches, drinks, and snacks to eat in the car. (love my plug in cooler)