We also live in the upstate. We take 85 to Lavonia, GA. Drop down through Ila to Athens to Madison to Monticello (take one exit up on I20 as you cross) and head down towards Macon through Juliet on 83 I think. We connect back up with I-75 in North Macon at the Riverside exit and head down. Once we get near Orlando, we take the road through Clermont instead of heading all the way down to I-4. I know that may seem round about to you, but we never hit Gwinnett/Atlanta/285 traffic and we don't have to worry with beach traffic or Jacksonville traffic or race traffic. We never hit any snarls. If we drove straight through (which we can't seem to do), it would take us about 9 hours. My parents live in Columbia and tried 75 their last trip instead of 95. Only added about 20 minutes to their trip and saved lots of headache.
If you need more specifics about great rest stops, hotels along the way, or specific road numbers, just let us know.