Isn't it true that the Model S can be placed in "range mode" to reduce the amount of battery energy used to heat the pack? I think I recall hearing that there is a way to essentially tell the car to tolerate a lower pack temperature, that is, lower the temperature threshold at which the battery gets heated. If so, this might be the preferred way to operate the car on cold days when making short trips.
With no cabin heater usage, the LEAF is reported to lose about 1% of its range for every four degrees Fahrenheit that the battery pack temperature is below 70. (See
My Nissan Leaf Forum View topic - Range Chart) So, at freezing, you'd expect 10% less range. Personally, from my experience and non-scientific measurements, I think it's a bit worse than that, but probably no more than a 20% drop at freezing.