It's not just the legacy manufacturers that are "slow off the line", but also the legacy consumers/drivers.

Climate does affect what a consumer drives. The driving culture is different in California than it is in all of Canada simply because of the vast differences in climate and how drivers negotiate the difficulties of driving and maintaining a vehicle in the winter. EV battery range, life, and performance are impacted by cold weather. So the shear price and inefficiencies of EV battery technology are enough for someone to keep driving a gasoline powered vehicle especially in cold ass climate.

Legacy consumers are less likely to take a leap of faith into a new EV as EVs haven't proven reliable in cold-weather conditions in the eyes and minds of the consumer -- yet.