I'd make the Holmes County area in Ohio a "must see" if I were you. Its south of Canton, Ohio and smack in the middle of Amish and Mennonite country. Check out Millersburg, Ohio and quilt shops near there. Many of the businesses employ local quilters. You can see web sites for many of these prior to your trip. Helping Hands has terrific sales.
Here are some quilt shops:
Miller's Dry Goods - in the village of Charm, Ohio
Helping Hands - Berlin, Ohio
Zinck's Fabric outlet - East Berlin, Ohio
Grandma Fannie's Quilt barn - Berlin, Ohio
Swiss Village Quilts - East Sugarcreek on St Rt 39
I imagine there are more - contact 1 & you can get a list.
Also, go to this site for Ohio quilts for sale:
Ohio-travel.suite101.com/article.cfm/buying-a-quilt-in-Amish-country.
My hubby is from Ohio & we used to live near this area.
Not quilting, but also a great store to visit in the area is Lehman's in Kidron, Ohio- Google it & see all they offer for the home, garden, etc, much of it crafted by or sold for the Amish & Mennonite. Run by Lehman family for generations, it was originally founded to serve the non-electric needs of Amish families, & still has many items for a simple life. I buy canning & kitchen items from them - order on line & have it shipped to me.
Have a wonderful trip, even if this location is not in your path. It would be so fun to travel with a quilter who understands that your car brakes for fabric.