I read where someone built an electric plane and shipped it to the south pole for testing so clearly cold is doable. Not sure how high the plane is designed to fly but the higher the colder it gets.
One thing I never knew about EV's is how Tesla owns that market and seems to be pulling ahead more each month. Their lead in technology and software may rule for many years to come. The old line car companies seem to be only retrofitting ICE chassis with electric motors. On top of that Tesla is patenting the technology that may very well become the industry standards and the other guys will being paying royalties forever. Any company that do not do their batteries themselves do not have a chance at long term success if the 100+ year history of the automotive industry tells us anything.
The below opened my eyes on the EV trend and trend setters.
Tesla Model 3 Is 219's Best Selling Vehicle In Dutch Lands | CleanTechnica