Perhaps someone could meet you at the airport & shuttle out to the decent roads. Either start in Murfreesboro or get a send off from the club in Wilson County & leave from Mt Juliet or Lebanon..

is a high volume & not cycling attractive road. We met a cyclist from Johnson City on BRAT. See if Johnson City has a club (I think so) & hook up with the Knoxville club. We can get you to Crossville.

http://www.granfondocycles.com/club/cycling_club_leisure.html

Is probably a good source for LD routing info per the Randonnuering riders there.

They have a cue sheets for Mid-TN to Chattanooga on "safe country backroads" at the bottom of the page.