I have a 2014 Model S 60, purchased just before Christmas when temperatures for the following week was hovering at around 0C. At that time, my 90% was around 255-265. It has since been getting colder, with yesterday hitting -15C, and my 90% was just 250. Today and over the next few days the temp has dropped to around -20 to -25C and I can see that my rated range is now just 245km. As far as I am aware, it's actually beneficial (somewhat) for the longevity of the battery to be kept in in cooler conditions, but does that include double digits below freezing? My car is kept in an open garage. It is connected to a 32amp 240v outlet. Does keeping the car plugged in do much to 'maintain' the car. If plugged in, will the car heat up the battery to 'maintain' it? Does anyone see similar loss of rated range in such temperatures?