Tesla drivers in Canada, in -10 to -20 deg C (14 to -4 deg F) temperatures, find their range drops up to 35% and as low as 55-56% of normal during cold weather.
Also, Superchargers are unable to initially rapid charge batteries when they are so cold. Tesla incorporates battery heaters that can heat the pack in preparation for taking a larger charging current but this lengthens the overall recharge time.
Many drivers leave their vehicles plugged in, in a garage, overnight, so they can be pre-heated (both battery and cabin) in the morning before driving to work. This works for driving to work but for the return trip at the end of the day, the vehicle is generally not pre-heated. Some heat their garage to keep their EV warm but this may produce more CO2-emissions if your heat comes from burning fossil fuels, or your electric heater is powered by a distant coal- or natural gas fired power plant.
EV owners say the range degradation doesn’t matter – because they are only driving short local trips. That suggests if you need to make long trips in winter, then you may want a gas-fueled vehicle. Gas engines also operate at less efficiency in extreme cold; however, vehicle range remains longer and “re-charging” by fueling up is vastly faster than plugging into a charging station.
They recommend if you live in cold winter climate areas (which is most of the landmass of North America), then you should opt to spend more on the optional larger battery available for some EVs. Of course, battery packs gradually lose capacity, over time. In that case, your range during winter would be cut quite a bit. (Note – Actual battery life varies considerably depending the manufacturer, how it is used, how it is charged, the age of the battery – some real world Tesla batteries have gone much further than 100,000 miles without significant capacity loss. Battery pack replacement costs vary depending on the vehicle and seem to run from about US$5000 for the smallest packs to about $25,000 for large packs.)
In 3-5 years, newer battery technologies may reduce the cold weather problem.