It's not so much a worry as an efficiency thing. If your in a cold climate that needs resistive heat its a lot less efficient to burn natural gas at power plant

It's not so much a worry as an efficiency thing. If your in a cold climate that needs resistive heat its a lot less efficient to burn natural gas at power plant at 50-60% then turn to heat with a resistor in your house, than to burn it in your house at 80-90% efficiency. Thing about a heat pump is it basically turns into a resistive heater once it can't capture any outside heat, then you just have heat of compression. This changes with a lot of renewable and nuclear power, but also heat pumps that can keep operate rating above unity in those cold temps really start making sense.