Done both from SW Va and we now do ONLY the Chattanooga way. We used to vary our scenery by going both ways, but after getting stuck in traffic or at least having very steady 80 mph traffic going around us (we usually tow at about 65 mph max) and then being stuck in traffic early one SUNDAY morning in Atlanta, that was the last time for us.
Checking the weather, it's supposed to be 87 on Thursday and Friday with a 0% and then a 10% chance of showers. The lows will be in the mid-50s, so I wouldn't worry about fog.
Just my $.02 worth from a 4 times per year trek south experience over the past 10-12 years.
