For a Leaf with the heat pump, Winter driving means about 1/6th-1/4 less range in temps above freezing, and 1/3 to 1/2 less range in sub-freezing temps. For a Leaf without the heat pump, it's more like 1/3 and 1/2. In temps approaching 10F and colder, the advantage of the heat pump is almost nil. Which Leafs have the heat pump? None of the pre-2013 cars have it, and from 2013 through 2016 the SV and SL trims have it. I'm not sure if the All Weather Package arrived with the 2017 model year, or with the 2018 rollout of the Gen II Leaf. From 2018 through 2021 (IIRC), the SL came with heated front seats and steering wheel, and the heat pump standard, while the SV only got them with the All Weather Package, and the S only got the heated seats and steering wheel (plus a rear HVAC duct) with that package. The heated seats, etc and heat pump are once again standard on both the SV and SL.