Although it doesn't answer your initial question, Thermal Curtains.
You may want to review why your heating or cooling so much.

To provide you with my experience, we have in the past heated our house
hold to a ridiculous degree to compensate for poor insulation in the
attic space. The previous owner's installed a nice shower stall;
however, who ever did the installation didn't insulate around the stall
and the air from the attic was comming in and freezing the pipes, and
us in the master bedroom.

Adding some insulation has let me drop the house temperature down while
we're not here. This is reducing the amount of on-time the furnace is
going through and saving both on our electricity and oil consumption.

Regards, JW