This reminds me of something I've been wondering - I've seen tips about turning the climate control off or setting the temperature low so the ICE warms up fast and doesn't stay on due to "heater setting". But if the HVB is too cold, then EV mode is either unavailable, or power is very limited.
So, is it better set the temp up and set the climate to Auto letting the ICE run and warm the cabin quickly, so that the cabin heat will help warm the battery?
It sounds like the worst case scenario would be to get in a below 0 F car and turn off the climate control, thinking you're going to get the ICE up to temp quicker. With the heat off, the HVB never warms up, so the car little to no EV power. All the while, both you and the car are freezing.
Disclaimer / confession - I haven't turned the heat off completely, but I usually set it to 72 F, floor only, with the fan at 1/3rd or so. The cabin heats up, but it does take a while. I do use the block heater to preheat the engine, and the seat warmers help me warm up, but do nothing for the HVB.