We turn our heat down at night (not off, just down to about 55-60; you do not want the pipes to freeze) and just put extra blankets on the bed.
Look into heating your home with a woodstove. They are extremely efficient heaters and cost nothing if you have a source of wood (and you can find it free all the time during the summer, at least in our area, since there are lots of trees -- my parents, who heat their house primarily with wood, just go and get ones that have fallen over during storms, so it's not damaging the forests).
Don't get one of those space heaters and leave it on all night; those things are extreme fire hazards.