That’s probably the best time to go. Very few cars, just watch out for the runners/walkers. I have seen a few that like to run/walk in the road at that time.
With stone mtn you have a 5 mile inner loop and an 8ish mile outer loop. If you do the outer loop be careful on the descent near Venerable lake, where it links back to the inner loop. It quite a steep one.
I agree that is probably the best time to go, especially if it’s a weekday. The inner loop is 4.8 miles and the outer is closer 7ish miles at least by my Garmin. Definitely take his advice on the descent by Venerable Lake. I come out of aero for that one. Although you could go counter-clockwise and climb it.