you dont get the condition of having your battery level halved due to cold weather, nor have the battery on an "always on" state because lion battery's only operate at a certain temperature range. theres a lot of losses on cold weather caused by the use of lithium ion batteries in general.

just because battery capacities on cars should go down doesnt mean cars wont offer a "long range" option for users if they need it (tesla for example litterally does), its just the everyday one needs to go down. having extended range on all cars is a solution to a problem that affects the 1% situation, and is impractical to apply the fix to the general fleet.