59f? Pfft....I go 56!
My house was built in 91 and has the orginal windows, not top of the line by any means. I put plastic in the bedrooms and bathrooms (keep it off the kitchen in case we need to air out and the living room for the rare warm day.) Our windows aren't overly drafty, but I don't notice them when the plastic is up. I don't find it makes a difference with the radiating cold. Do I make my money back? No clue, but those 10 degree windy nights without a draft is worth it for me.