I'm also from the Cincinnati area. How did I miss this thread?
We've never driven straight through to Orlando. Closest was leaving at midnight and getting to Gainsville about 3 PM (we were stuck in an hour-long traffic jam at Lexington...horrible wreck). My daughters (at the time about 10 and 9) slept until about 7 am...just north of Atlanta. We took our time getting down there...our reservations weren't until the next day anyway.
Few things...
1) What day of the week are you travelling? We travelled down on July 4th, so we didn't have to worry about rush hour traffic. But on a weekday, if you left at midnight, you'd make Atlanta right about morning rush hour. And you'd want to avoid Atlanta at rush hour.
2) Wreck near Lexington is an aberation (we think they were Parrottheads coming home from a Jimmy Buffett concert who had just a few too many margaritas). The drive is nice and smooth. You'll have no problems going through the mountains. And if you decide to leave a little later than midnight (maybe 2 or 3 am), you'll probably catch sunrise over the mountains. That is beautiful. And might be a better option...it will get you through Atlanta after rush hour and you'll reach Orlando in early evening.
3) After your kids wake up, you gotta let them outta their car seats to run around. That's what rest areas/welcome stations are for. And if you don't mind McDonalds for breakfast/lunch, let them run around in their playland for awhile. Chik-fil-a also have playlands as well (not applicable on Sundays as they are all closed).
4) At the very least, stop at the Florida welcome station. That is a tradition, every time we drive to Florida. Free orange juice, travel brochures/coupons, and the opportunity for your kids to run around. Plus, the satisfaction of knowning...you're almost there. (Yes, I know you still have four hours to go. But it's still a cool feeling. I actually feel that way, when I stop at the welcome station, and we still have an eight hour trip to Miami....with an overnight stay in Lake City).
5) Speaking of Lake City, that's another good place to spend the night. It's about an hour south of Valdosta, and not as pricey. It's 2 1/2 hours from Lake City to Orlando; 3 1/2 hours from Valdosta to Orlando and about 4 hours and 15 minutes from Tifton to Orlando.
My thought...you can probably go down in a day, but I'd take two days going home. The trip back is a bummer, without having to make it in a day. Make sure you get past Atlanta before stopping.
Have fun. And when you're driving by Erlanger....take me with you?
