Not so much capacity, but being cold makes the chemistry reluctant to give up it's stored energy. So you charge at room temperature, to full capacity and then take it out in the cold. It'll sag more under load as it cools down, and so at the same load, it will hit LVC sooner. If you then return it to room temperature (without recharging), it will "give up" the rest of the stored energy.
This effect starts to be noticeable on my ebike pack at about 5 degrees above freezing, by about 15 below it's quite apparent but the pack still functions. I bring the battery inside with me where ever possible at these temperatures. At 30F I wouldn't expect much effect, unless you're pulling especially hard on the pack.
Mine is a 20Ah pack (48V) pulling 25A. Capable of much more though, 100A+ so that might have something to do with why it's not super apparent to me.