1. Do some shakedown rides. Take a really long ride -several hundred miles- so you can figure out what a realistic travel distance in a day would be. Build your itinerary around that.
2. Gel seat pads and bar-end weights. Make your bike/s as comfortable as possible. Check the harley davidson supplier websites out.
3. Networking. Develop a network of stores or individuals who can help you when something breaks on your bike, also get handy enough with every aspect of your machine so you're not dependent on the kindness of strangers to keep moving.
Good luck with this, its a cool idea.