Fast Overnight on I-85 between Charlotte and Montgomery

I'm plotting a route heading south on I-85 and it looks like we'll be wanting a fast on/off overnight along I-85 in the general vicinity of Atlanta. All the sites on RV-Parky looking north and south of Atlanta show No Overnight Parking at Walmarts, Cracker Barrel, etc. Allstays shows only expensive RV "resorts." What's up with this route, anyway? Is there some alternative road that won't slow us down too much and which might afford someplace to just stop for a quick night's sleep? Or any locataions near I-85 which I haven't found?

Thanks for any help! We're not looking to "camp"-- just sleep and hit the road again.