I can tell you that at about 1.5 degrees further north in New Brunswick I lose about 1/3 range when we are in the -10 to -25C range in my 2015, less so (1/4) in 0 to -10. In summer I'm pulling down 100-120km with little effort, but in deep winter on the same roads I am getting about 80-90km in.
Below -20 I tend to take the ICE on the 30km runs into town, unless I'll be near the charging station in the city. I still prefer the Leaf if I can manage a short charge (and preheat) while in town.
The heater is a problem so run the heated seats/steering wheel, and preheat when you can. The deep cold really knocks back the output of the traction battery but don't let it discourage you too much. Energy management is what it's all about. Wear a coat, bring some gloves for the REALLY cold nights, and enjoy your silent ride.