I gave up reading, does it ever get to the point of telling us what to do to make batteries work in the cold? Or does it just endlessly attempt to say that petrol cars have similar winter issues?
So how would a frozen car become warmer with a blanket, unless some subsystem within it is emitting energy?
But even once the car is stationary, a blanket would help it retain the heat generated while driving, or generated from charging now that it's plugged in.
Probably a reference to the well established practice of using block heaters[0] on diesel engines in cold climates... which AIUI are effectively just electric blankets. It's why you'll often see what appears to be a short extension cord dangling out the front of a big old truck where it snows a lot.
Obviously on an EV you already have much of the parts necessary to generate the heat, esp. if plugged in to charge... so it could just need the blanket/insulation part.