If it were me, and I really wanted to avoid Atlanta, during a really heavy traffic period, I would get off I-75 at Calhoun Georgia, head south on GA Highway 53 to Rome, there I would catch US 27 and take that south all the way to I-185, south of LaGrange. Then in Columbus, stay on the expressway which becomes US 280, and then GA hwy 520 and then US 82 (all the same 4-lane divided highway) through Albany to catch I-75 at Tifton GA. It sounds complicated but it's not and it's mostly 4-lane divided with light traffic. Actually, on January 3, I'd take US 19 south out of Albany GA to I-10, and avoid all the heavy southbound traffic on I-75 in south Georgia. JMHO