Too late to help you now but maybe you can use on your next trip.
There's great BBQ on I 24 S and I 75 S between Nashville, TN and Florida. Go to Jim and Nick's at Exit 78 B in Murfreesboro, TN. Jim Oliver's Smokehouse and Lodge at Exit 134 has outstanding southern country food including BBQ serving breakfast all day and dinner in the evening in a very nice atmosphere. There's lodging as well if you you want to stop for the night.
Get off I 75 at Exit 333 in Dalton, GA and go E on Highway 52 to Glenwood Ave. Take a left and go to E Morris. Take a right and go 4/5 blocks to Miller's BBQ for good road food. Get off I 75 at Exit 290 at Cartersville, GA and go W on Canton Highway to the dead end at Highway 61 and go S to Slope's BBQ for good road food. Get off I 75 at Exit 263 at Marietta, GA and go E on S Marietta Parkway to Powers Ferry Road. Go to your left and go to Roswell Road to Williamson Brothers BBQ for good southern BBQ. Get off I75 at Exit 187 and go S to Johnston Street. Take a right and go to Grit's cafe for outstanding southern cooking for lunch or dinner. Get off I 75 at Exit 169 at Macon, GA and go SW on Tom Hill Blvd. to Riverside Dr. Take a left and go S about a mile to Fresh Air BBQ for outstanding GA smoked BBQ. Get off I75 at Exit 63A at Tifton, GA and go W on 8th Street W to
Pit Stop BBQ for good road food. Get off I 75 at Exit 22 in Valdosta, GA and go E on Valdosta Road to Smok'n Pig BBQ for Top 10 in the US BBQ.
Go to Puckett's when it's convenient. Their BBQ is not what they are famous for. They have outstanding country food but BBQ is just a small part of it. Good luck. Drive safe.
Jim and Nick's BBQ @ 436 North Thompson Lane, Murfreesboro, TN 615 - 893 - 1001.
http://www.jimnnicks.com/ Jim Oliver's Smokehouse Hotel and Lodge @ 850
West Main St., Monteagle, TN 931 - 924 - 2268.
http://www.thesmokehouse.com/ Miller Brother's BBQ @ 606 East Morris Street, Dalton, GA 706 - 278 - 7365.
Slope's BBQ @ 1133 North Tennessee Street, Cartersville, GA 770 - 386 - 9090.
http://www.slopesbbq.com/ Williamson Brothers @ 1425 Roswell Road, Marietta, GA 770 - 971 - 3201.
http://www.williamsonbros.com/ Grit's Cafe @ 17 West Johnston Street, Forsyth, GA 478 - 994 - 8325. LD. I75/EXIT187.
http://www.gritscafe.com/ Fresh Air Bar B Que @ 3076 Riverside Dr., Macon, GA. 478 - 477 - 7229.
http://www.freshairbarbecue.com/ Pit Stop BBQ @ 1112 8th St. W., Tifton, GA 229 - 387 - 0888.
Smok'n Pig BBQ @ 4228 N. Valdosta Rd., Valdosta, GA. 229 - 245 - 8227.
http://www.smoknpig.com/