Litium ion and all mainstream battery technologies are fluid based and cannot operate in extreme cold.
That's why EVs have a system to keep the battery pack warm.
That's why EVs have a system to keep the battery pack warm.
(My personal experience with EVs in the cold only goes down to -10C, with the vehicle parked outside overnight, no charger connected. I saw no issues expect for increased energy consumption.)
The range is bad in winter but fast charging produces a lot of heat in the battery, you can see steam going from below the car while charging, that can then be moved to the cabin after. So long trips aren’t that bad. But you spend more, for sure. And you need a good winter EV. A lot of EVs on the market are terrible winter EVs.
Also, you don’t keep the battery warm all night as it would waste too much energy, but you should pre-heat the battery if you want descent battery performances immediately after you drive. On my car, it takes a few minutes while connected to the wall. I can start it from the phone or program it.
Around here it's -5 to -7, so much less severe and if I understood my wife correctly, the Ora has a ~20% drop in range. Still good enough for our use case, but when I'll replace my PHEV with a proper BEV this might be more relevant.
About the worse EVs for winter, that would be the ones with no or small battery heaters. The old imiev for example.
A 20% drop of range by -5 is pretty good. Your wife may enjoy a cold interior or trust the temperature display of the car AC.
And oh well, ours would be pretty good then, but sadly I just got new data from her: 30% or 260km down to 160km, and the lowest temps for the last days were only 0 to -5 degC. Still good enough for her daily total of 60km. One big factor: The dealership didn't want to add the heat pump, and we didn't want to pay that extra in full for a car we would not keep anyway (plus we were lucky and could get the car from their stock).