Well, I've Volkerized, and can't find anything resembling an answer to the question I'm about to ask, and further, unfortunately, since there are about 5 threads involving cold weather, I'm not sure which to post in, so I figured I'd just start another one. This is a question that might be best answered by someone in a country like Norway who has had his/her Model S for a while.
It is clear that in cold weather, your energy usage is increased, as measured by Wh/mi, probably because of some combination of loss of efficiency when the battery is cold, energy required to heat the battery, and energy one might be using to heat the cabin and/or the seats. When I drive the car now, here, during the few days when the temperature starts off at or near freezing, my energy consumption is greatly increased _on my roughly 7 mile trip to work_. The normal pattern is when temperatures are more temperate is that when the first 10th of a mile ticks off after charging, it says I've used anywhere between 500 and 1200 watt hours / mile (probably because it is counting energy used while charging and sitting there since it first started charging), and then as I drive, the average since charging drops until it winds up somewhere usually below 300 Wh/mi. In cold weather, over the 7 mile drive to work, it seems to stabilize around 400 Wh/mi.
So my question is (I suppose I could do an experiment this Saturday morning if it is cold), what happens after you drive for a while. Does use of the battery generate excess heat which warms the battery and once it is warm, it stays warm without using more energy to heat it than it normally would, and maybe less energy to cool the battery, so that if I went on a long trip, once the initial burst in energy use was done, aside from seat or cabin heat, I would not use much more energy than normal?
I'm thinking of the because I'm going on a 300 mile trip next week and want to know what to plan for. Anyone on Norway? Northern Minnesota?
(I might start it up early in the morning, drive the 40 miles or so to a Supercharger, charge it again to start it's average Wh/mi over again, and then drive back to see what things are like on the return trip.)