I saw one graph that said a 32% reduction in range at freezing vs 20 degrees though I can't find it now. Colder would be more, but would you hit 50% reduction that would make 150km round trip iffy? Hard to say.
https://www.auto123.com/en/car-revie...y-range/65676/
Might want to find a Bolt owners forum and see if there's any Canadian owners that can comment.
EDIT: This suggests that -30 might get close:
https://www.geotab.com/fleet-managem...perature-tool/ (the tool is kinda broken for me, I could only get down to -23 for 175km)