Some of my favorite rides have been in Tennessee. I've done organized tours there, but it's a very doable area on your own, too. Lots of good roads with wide shoulders. I'd like to do a long weekend out of Franklin Tennessee soon. That's just south of Nashville. There are some good cycling guide books of the area btw.

DH and I are planning on the Katy Trail next year. We're also hoping to visit the Finger Lakes area of New York, although we also plan to do some hiking.

We're also in Indiana. How far are you willing to drive? Our limit is about 10 hours at the point. With that in mind, Michigan and Wisconsin are good options, too. Some friend did a self supported tour along the Western shore of Michigan a fews ago. They had a great time.