How does denim insulation perform at low ambient temperatures?
you can use this far better frost avoidance and cold draft reduction . good to -40’C
https://www.homerepairtutor.com/how-to-weatherize-windows-with-plastic-film-insulation/
I made insert frames and heat shrunk onto then remove and store in spring. But getting an air flow seal is best. They will inflate if not tight.  Easy to install with a hair dryer,  not too close .(6”)