837 miles
We drove from Virginia to Savannah and stopped for the night on the way down -- that took about 8 hours. Then from Savannah to Orlando took another 4 hours.
On the way back, we left at 6am and, counting potty breaks and gas fill-ups, were home at 7pm the same night.
For us, it's not that bad of a drive.
To fly would mean driving to the airport (1 hour), hanging around the airport before our plane departs & going through security with four kids (2 hours), sitting on the plane (2 hours), changing planes in Atlanta and hanging out at their airport (2 hours), getting on another plane to Orlando (1 hour), finding our bags and getting a rental car (1 hour).
You're at 9 hours already. Tack on another 3 hours and we can drive it ourselves and save thousands in airfare, plus the cost of a rental car.