We live in California, not on the coast. Up in the Sierra Nevadas. Summer is DRY. Wool in the dry summer heat feels scratchy against the skin. I love it in the winter, especially if it's a damp day. Don't know how it would work in the dry summer sandwiched in a quilt.
Is it to used as decoration on a bed? For a summer blanket?
Just this past Saturday, a lady was demonstrating a pieced tablecloth. She serged the seams and mitered the edge to fold back instead of binding. It was thin like most tablecloths and draped beautifully. No need for a backing. The seams were thin so that glasses didn't tip. I think this could be an answer for a pieced spred for summer.