I want to insulate the inside of a wide (double) garage door at my Dad's house. It has a roll of glass in it but that is already cover with aluminum foil so visible is not an issue. What is best? I was thinking of using duct board and cutting it to fit in the different sections. How does that sound? Or is there something I could get at Lowes that would be better? Thanks in advance for all the great advice you provide on this web site.

P.S.: The door will still have to open and close.