(hackeridiot12 may be Jewish - IME Jews often type "G-d" because spelling the deity's name in impermanent text is disrespectful. Bit odd from my perspective, but harmless :))
Foundation licensee here in the UK, working on my Intermediate (and hoping to pass that exam this year). I manage the radio system for the UK Discworld Convention (every other year, next instance August 2026), and I spend a chunk of time on the VHF repeater near me, in the Cambridge area (mostly listening).
Yeah, I'd like to see those figures too, and I think they might surprise you (and me). I don't have figures or references to hand here, but as I understand it modern heat pumps should be good down at least a little way below freezing. They're widely used and popular in Norway, for example, and the Norwegians aren't exactly new to cold weather.
In the context of heat pumps, a "backup heating strip" is a resistive heating element - electricity goes in, heat comes out just like an old electric heater. They're generally used during defrost cycles for the external air handler in cold weather, or to provide a temporary thermal boost when the heat pump is having performance trouble e.g. when the exterior temperature is near the bottom of the heat pump's operating range.