Anything requiring routes east of I-75 in the Atlanta metro area is tough. Having lived in and around the Atlanta metro area and north Georgia most of my life and RVing east of Atlanta for years my sense has been its just hard road anyway you cut it. Best just to catch it during non commute hours. I-285 around the east side is marginally tolerable during off peak hours.
The good news is for north- south travel on I-75 (or west of that corridor) there is an excellent west side total bypass of Atlanta in place from Calhoun, GA, to Rome, Carrollton, LaGrange,Columbus, Albany and tifton. 4 lane and highway speeds all the way. Only a few stop lights along the way.Nice spacing of towns and services. Its the best kept secret in this state and few folks are aware of it. I've timed it running using the Atlanta 285 corridor and this US 27 route and it comes out too close to call. But the west US 27 bypass is sooooo much more relaxed and easy for RVing.
The route uses much of the new and upgraded US 27 /Georgia 1 corridor. On the north end one connects with I-75 at GA 53 which connects in Rome with US 27 (Ga 53- to Ga 1 to US 411 to US 27 for the truck bypass around Rome). Then one can take US 27 south to LaGrange and connect with I-185 to Columbus/Ft Benning. At Ft Benning enter US 280/GA 520 to Cusseta and the either US 27 to Tallahassee or continue on US 280/Ga520 to I-75 through Albany to Tifton. We are now using this route almost exclusively to get around Atlanta and move north/south through Georgia.At LaGrange one can catch I-85 and move southwest towards the Gulf as an option also.
I'm sorry it may not be of much help to the OP if for some reason you must stop in on the east side of Atlanta. But if your route is exclusively to Foley, It will work if you would explore using I-40 to Knoxville, then I-75 to Calhoun, GA. Exit Calhoun and follow the US 27 route to LaGrange and pick up I-85 south to Montgomery then I-65 south .
Wanted to throw this out there to make sure you were aware of this alternative