[nickvanw]

I'm in Seattle, my new-ish townhouse has a heat pump and it's never been too cold for it to be functional - it's worked hard some of the really cold+snowy days the last few years, but never to the point where it wasn't heating the house up perfectly fine.

I am not sure I would pay $27k for the whole install, but once it's there I've found it to be great. Extremely inexpensive to run and with all of Seattle's power being carbon-neutral, totally guilt free to set it to 68F at night during a hot summer day.