I don't know where you are starting from except western Ky. Might be a little longer but not much, to come east of Atlanta. Problem might be the mountains in western NC. Sounds silly to Carolina to get to Savannah, but time wise you might save it.
Atlanta is prtty much of a roll of the dice on traffic issues. When we go come home from S Dakota we cut off of 75 in Dalton and then to Dawsonville, Gainesville to Athens. Not interstate speeds but we like that part of the country. In Gainesvillle just get on 129 toward Athens. Athens bypass (Ga 10 loop) to US 441 to Watkinsville exit. Follow US 441 to Madison, Eatonton, Milledgville to Dublin. Dublin get I-16 to Savannah. Going to be some truck traffic on 16 because of the Port at Savannah is a busy place. Not a bad ride until 16 then it is just boring to Savannah.