Incorrect, efficiency drops as the temperature differential grows. This is a basic law of thermodynamics, since you can extract energy from a temperature difference, it must require energy to create one.
Absolutely true - efficiency drops. Electrical consumption also drops if your heat exchanger can't scavenge enough heat from the air to vaporize your refrigerant. The compressor must slow down.
Or as I pointed out - you can activate a backup heat source which causes a huge spike in electrical usage. Probably better than freezing however.
My heat pump is 11 years old and doesn't have a resistive heater. I thought resistive heaters were a new thing. Many people in the Northern US and Canada need some kind of backup and a resistive heater in the heat pump would be a selling point for many.
