I've averaged 189wh/km since last August with just under 20000km. For the first 3 months or so, until the cooler weather came, I averaged 154. The battery heat really kills the range on short trips, but if you switch to "range" mode the battery heat will not come on until -10C or so, saving that big initial hit on most cool days. The disadvantage is that regen is reduced or nil for a much longer time and power may also be reduced. "Range" also limits heater output.
If you can time the charge and preheat to be completed just at departure time, the battery will be warm to start and probably won't need heat. Also regen will not be limited as much if at all. Even with these techniques, the cold will really increase consumption, especially for the first few km.