Actually, these electric heat puswork well pretty in houses under 2000 square feet and they seem to work in lower temperatures. We have an older model for a larger house and ours doesn’t work brown 40 degrees. We have a propane back up heater and a whole house generator.
Providing your house is EXTREMELY insulated which poses another problem in northern climates due to the abundance of hunidity. Mold is the next big cash cow for ambulance chasing attorneys.