Reading the double pane to single pane topic galvanized us this weekend to start and complete a simple project that we have talked about for years, it answered one of the issues brought up in that topic: single pane glass has zero insulating factor. Those two big windows in our coaches cause huge heat loss and the blinds are fine for privacy but do nothing to reduce heat loss.
Thinking about that we remembered how our Class-C had a Velcro held curtain for privacy that covered the front windshield along with the drivers and passenger door windows.
Off to JoAnn Fabrics and they has insulated curtain liner with both Mylar and poly batting quilted into it,
Are You A Bot? (https://www.joann.com/54in-ivory-warm-window/10674935.html?gad_source=1&gclid=CjwKCAiAgeeqBhBAEiwAoDDhn87-jHsyHbsoKNgmQa7GyJY5l4hK3xASmDYlyv3KskwBTf6v3rFcOBoCamAQAvD_BwE)
Then bought a nice fabric and two packets of Velcro sewable and adhesive type.
Made the curtain as two halves that also Velcro together, when down they weigh probably 3 lbs and both fold up about the side of two average sweaters, and keep them under the sofa .
Often in the spring and fall or during the winter those front windows are soaking wet with condensation. We have even had big sheets of foil bubble foil up there and on occasion furniture pass, not very elegant!
The whole project only Took us about 4 hours cutting and sewing, 5 minutes cutting down the Velcro to size and putting it in place behind the valance.