Thought of a few more shops:
Portsmouth Fabric, Portsmouth, NH (if you are driving up I-95 from Boston to Maine, you will drive through Portsmouth)
http://www.portsmouthfabric.com
Pinestead Quilts, Lincoln (don't know if they are still in business, but worth trying since you will be in Lincoln)
One Stitch Two Stitch, Littleton, NH (just north of Lincoln)
http://www.onestitchtwostitch.com
Again, have a great trip.
Anita