Cold in Iowa too used to cost around $300 to heat my house (28x54) we built in 1974 insulated around the basement walls with 1" styrofoam. locals thought we were crazy. Well turned out not so crazy., This year cost will be around $800 for the season. summer fill was $1.35 gal Dec was $2.01 still have about 35% hope it lasts through the month of March. Stay warm.