I would think that riding an EV Bike in cold weather would drastically shorten the battery life, especially if using 12vdc and or 5vdc accessories.
Required qualifier* battery chemistry can change cold weather performance a lot, and I won't pretend I'm an expert on the batteries in question
But that being said, lights, heated gear, phone charging, etc, are pretty much irrelevant. My average ride takes about 2 hours, where I consume 6kWh of battery over 35 miles. Just as an example, over that time, my aftermarket headlight consumes 60Wh of power. So if I turned off my headlight for that same ride, 6000/35 = 171W/mile, 171/120W = .7 miles. IE, If I had turned off my headlight for the entire ride, I would have made it 35.7 miles instead.
In other words, accessories barely matter. The motor consumes way more.
As far as winter vs summer, it is around 20% loss of range in the winter for my Zero. Granted, we don't deal with super cold temps here. 30-40 degrees F is what I'm talking about, compared to 70-80 degrees F in the summer. I have ridden in colder temps, but it didn't change that ratio much.
As for street battery range, the average speed and peak speed is what determines range. The Zero can go about 65 miles IF you keep it under 40mph. It is all about speed. At 55mph, max is 50 miles. 60mph, max 45 miles. 70mph, max 30 miles.
The range is linear to speed. Bikes are very bad when it comes to aerodynamics.
I expect the EX to be around 20% better numbers than that, but it will be equally as bad aerodynamically.