I believe they “just work.” Electric motors don’t stop working at low temps. I think it’s mostly just range that’s impacted since EVs can’t use the inefficient part of an ICE (e.g. energy produced by gas not captured by the powertrain) for heat, so they have to run heat pumps. (Along with battery chemistry not working as well in low temps)

EVs will maintain the battery temperature if plugged in, usually at 0C.

Even if not plugged-in they'll try to keep the battery above temperatures that may be damaging, e.g. -30C. This only works for a sufficiently charged battery.

EVs could (and some do) self-heat the battery when temps are low enough for damage