If you dress appropriately, then there is no such thing as bad weather (assuming there is appropriate dress for lightning or 150 mph winds, which there isn’t, but you get the point).
Dressed for the 2 deg F ride, I pulled the trailer chassis with the Grocery Getter App to Kavarna Coffeehouse, and I took this pic halfway across the Walnut Street Bridge. Note the solid Fox River behind.
After a cup of coffee and getting halfway home, the controller and motor shut off. The battery had been outside in the cold for roughly an hour and a half. I checked a plot of ambient temperature vs battery capacity, and sure enough, at 2F the battery capacity drops below half.
The Nissan Leaf has a battery compartment heater to prevent a similar occurrence, but I’m not sure it’s worth my time to develop something for the handful of people crazy enough to bike with cargo at that temperature…