My husband & I just drove down to Orlando from Milwaukee in November... we pushed & got to Chattanooga by 10pm the first day (that was after leaving a bit late & not stopping except for gas & potty breaks... ate on the road).
That left us lots of time the next day to do sightseeing. We stopped @ Lane Orchards (just south of Macon, GA) where they have lots of southern produce for sale (think Peaches & Pecans, jams & jellies!) plus there is a play area for the kids. I have pictures of my two Ridgeback boys, one on a John Deer tractor, the other on a Harnishfegger (sp?) Int'l tractor.
We then stopped for a wine tasting @ Horse Creek winery, followed by THE BEST catfish dinner in Adel, GA. "The Catfish House", which was just one more exit south (see their Facebook page for address & phone# to get directions)
I know driving through KY & TN, I wished we had more time to sightsee. There is tons to see in Chattanooga. I took the boys for a walk on the historic Walnut Street bridge.
My one warning about "cheap" lodging - I stayed @ LaQuinta in FL - great experience. Stayed @ Motel 6 in Chattanooga. On the way down, it was me & my husband, we were @ the one just east of Chattanooga, right off the interstate. Not too bad - outdoor room entrances, etc. typical motel. Didn't feel "unsafe" but it was the 2 of us & 2 big dogs.
On the way back, hubby had already flown home & so I booked a Motel 6 just outside of historic downtown Chattanooga. Indoor room entrances, locked lobby @ night... thought I'd be good. Was very nice when I checked in, but later that night when I had to get something out of my van, I thought I saw drug deals & prostitution pick-ups.
Spend a bit of extra $$ & stay in something LaQuinta or higher, esp when travelling with children!! People of ill-caliber don't spend the $$ to stay @those places.
One thing you can do while travelling state to state is to stop @ the visitor center (just inside the state lines along the interstate highways). Gives you a chance to stretch your legs, & also browse the brochures of things to do in the state. I've found the desk clerks are usually very helpful & offer their own recommendations as well!