Got the latest report from my son on his Chevy Bolt. The weather over the last few days has been fairly brutal with temps around 0 to 10 F, strong northerly winds, and heavy snow. They are anticipating -15 today. He says, so far, they have seen a 70 to 80km decrease in range (about 20%). Part of this is due to battery efficiency loss while some is due to the use of winter tires and the use of heater etc. The heater is good, and heat is instant. He hates the traction control and wishes the default setting was off so the car would get around better in the snow. I also hate electronic traction control on any vehicle, so I'm with him on that.
Even with the reduced range, the car is working out well as a daily driver. A trip into town is about 12 miles for them and a trip into Calgary is about 45 miles. The car is great for this, but it wouldn't make it to my place on its best day (about 270 miles). We are heading down to Moscow, Id, next weekend and they will be joining us there. They will drive their 13 year old Hyundai Sonata for this trip, as they do for any long trip.
So, as expected, the EV works great as a daily commuter and is not really usable for longer trips. There is a definite loss in efficiency in cold weather. This is also not unexpected, but it is manageable. WH