There's two different things for low-temp LFP batteries. One is low-temperature charging cutoff. The BMS has a temperature sensor and stops charging if the temp goes below freezing. For your situation, you need low-temp cutoff in your battery.
The other is low temp heating. This is in addition to low-temp cutoff. Some more expensive batteries have heating pads internally that will turn on when the temp goes below freezing to bring the battery back up to temperature.
can I leave lfp all winter (with them not being used)? I understand not charging them (which means I shouldn’t use an inverter/charger) in the cold.