Mounting solar arrays to the roof of a Bigfoot

"But I have found one or two occasions where I wanted it - several days parked under trees in heavy shade, cold temps so heater runs a bit. I had to move the truck into the sun for a few hours after 3 days."
I was in your neighborhood this morning at Bothe State Park where I was checking out the site where we are staying in a couple weeks. it was all of "cold and shady".