This is kind of odd. You mean that the battery can't take the power when cold? The obvious fix is to use that power first for heating the battery. You'd still

This is kind of odd. You mean that the battery can't take the power when cold? The obvious fix is to use that power first for heating the battery. You'd still slow the car via power generation, giving the exact same braking feel. Trains often do something similar, except that they dump the power as heat to the air. That would work too.