Well our plan won't help you if you don't like driving late at night! Our kids are also older, but they used the through the night drive to sleep the whole way down.
First trip in 2012, we left at 4am. But in 2014, we left on the Saturday night at 10:30 (this drive we took I75). We stopped for a quick breakfast break, and then hit the Marietta Diner (a Triple D stop) for lunch around 2pm. We drove until 7:00ish, and DH was done. I can't remember where we ended up, but we only had about 5 hours left to drive the next day. We were up by 7am (oldest DD actually had to log on to her University site and register for classes that day) and after breakfast in the hotel, we hit the road and made it to Orlando by about 2:00.
DH really liked the drive through the night - he spent Saturday evening napping, while I went to a play that our middle DD was in (hence the leave at 10:30 once she was off the stage!)
We didn't pre-book our hotel in Georgia, but we pre-booked our Orlando hotel. We stayed off-site (both trips) the night before we checked in to Disney - we wanted to have a fresh, early start to our first day at Disney,and not be tired from driving and miss part of our first ticket day. We stay at the Buena Vista Suites - awesome rooms & great breakfast for a great rate! We did some searching on Booking dot com to research hotels in the area that would work for the 5 of us, and I wrote a few names down from a few areas we figured we end up in by 7pm or so that first night.
Side story -we were super glad we did I75 and had the "along I75" book! I had updated our GPS before we left, and it gave me a message that there wasn't enough memory for the full update, so I chose the "update Canada" part. Well, that was fine, but it DELETED the southern states! We ended up hitting a WalMart in Marietta, where we bought a cord that we could update the GPS with and used DD's computer to update the Southern US part. Which left us without the Canada part until we got home and bought a memory chip for the GPS. Talk about a "second wind" at 1am when we crossed the border and tried to input the Georgia address we were aiming for!
Have a fun drive!!