It was high 20s last night at my MIL's house a few blocks south of Lake Ponchartrain in Metairie, LA. Woke up this morning and found that her new furnace couldn't keep up and the house was 2A below the 72A setpoint. My first thought was that she was hornswoggled by the HVAC contractor, but then I remembered she heats her garage. The house was a model home when she bought it in 1970 and the garage was used as a sales office. So now she keeps her quilting "shop" in the garage and heats and cools it all year. I could see how the contractor didn't size the furnace for that peculiar situation, considering the whole front of the garage isn't insulated or even sealed at all. Plus there are a couple of other doors to the outside badly in need of sealing. Trouble is she pays so little in electricity and gas (Louisiana, after all) that she has no impetus to do anything about it. So being the best of SILs I just turned on a couple of burners on the stove and brought the house up to the desired temperature until it warmed up enough outside to make it not a problem. At 95 I guess she can operate her house any way she wants.