> I think the biggest hurdle to heat pump adoption (at least in North America)

> When it's truly cold (like < 20F) the heat pump will run continuously and struggle to maintain temp.

Luckily, pretty much the entire Western and Eastern Coastal areas, it doesn't actually get that cold on a regular basis, except a few days in the winter. The US is actually in an incredibly advantageous geographical position for at least 60% of households to be on heatpumps, as opposed to, say, Finland/Canada/Russia etc.