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).