Atlanta to Athens by Bicycle

I'm trying to figure out the best way to make the trip. Keep in mind, the farthest I've ever ridden in a day is about 20 miles, and that was in 4 mile shifts.

But I've sort of set the Atlanta to Athens trip as a goal for myself. I'd like to be able to get up early Saturday morning, start biking, and reach Athens before sundown. In my head, I get to Athens about a half hour before the sun starts to set, then meet up with my friends at a restaurant to eat salmon and drink beer. Later, there's a concert and three to four naked ladies.

If I tell google maps to avoid highways, the trip is about 66 miles. Assuming I could maintain a good speed throughout the ride, it's actually doable.

After this, I'd like to try an Atlanta - New Orleans ride.