Easiest way to model this is from the cells impedance. Essentially think of the cold limiting ion motility in the electrolyte phase, and that resulting in a higher impedance, that works out as a voltage drop at the cells terminals, so the cell has a limited depth of discharge, vs at higher temperatures.

You can read about EIS here: https://www.gamry.com/application-notes/EIS/basics-of-electr...