Course recon drive with two of my kids through Adair, Union, Clark, Decatur, and Ringold ‘does anyone live here?’ Counties. The roads are rough in spots, but generally in great shape. Only saw a few cars in over four hours of driving. The one water crossing we saw was down to a trickle. Only one re-route for a bridge out; I doubt it will be fixed by October.
I highly recommend using both a Garmin and the cue sheets. Your chance of success will significantly increase if you have both. There are street signs that are missing, shot to hell, or otherwise unreadable, and road names that may show on Garmin navigation or Ride With GPS that will not match your cues. The cues match the road signs that are there, but when they aren’t, you’ll want the GPS.