A lithium cell at 32°F delivers roughly two thirds of the usable capacity it delivers at 68°F. Nothing is broken — the chemistry simply moves more slowly, internal resistance climbs, and the controller cuts out earlier because it sees a sagging voltage rather than an empty pack.
The practical consequence is that a commute you comfortably cleared in October leaves you pushing in January. The fix is not a bigger pack; it is keeping the pack warm until the moment you ride.
Store the battery indoors, charge it indoors, and fit it to the bike as you leave. On a long stop, bring the pack in with you rather than leaving it on the frame. And charge to 80% rather than 100% if the bike is going to sit for a week — a full pack held cold ages faster than a part-full one.
