Here are places I recommend:
Dephines in Gaylord about 2 hours south of the bridge...(about 8 minutes off I75)
Bittersweet Quilt Shop in Pinconning (about 5 minutes off I75)
The Bay City, Saginaw, Midland area have quite a few shops. Material Mart would be my choice if you had to choose only one.
I'm not familiar with any more shops off I75 south of Saginaw.
Fabric Shack is in Ohio....I haven't been there but hear it's a worth the stop. If you call them, they can tell you of a nice place to eat nearby.
In Knoxville there is Mammaw's Thimble Fabric & Quilt Shop.
Summerville, SC is a pleasant town with Sew 'N Sew
Middleton Plantation is an interesting visit with a nature area near by. There's a short trail to stretch your legs.