As far as I understand it, sitting in the cold is not so bad, as long as you have items that normally suck battery turned off (e.g. sentry mode). Also, if you warm the car up about 30 minutes before driving, then the battery gets warm enough that a) will be able to regen properly; b) you will get the full battery level from the warmer battery (ie won't get the grey'ed out part of the battery when it's cold).
For the SR+ which is 1 motor only, it means then that during the "warm up" your motor will run to warm things up at about 3kW, which means you use about 1.5kW of energy. Let's say other things also use about 500W, so 2kW. so that will be about 4% of battery.
At the moment, (per one of Bjorn's newest videos) LFP SR+ is rated with 53kWh of energy, plus another 3kWh of buffer. So let us just start every day with 53kWh, and because LFP, you are charging every day to 100%.
With that, let us say that we lose about 20% efficiency because of winter, so instead of about 400km of range, you get 320km. You minus your 75km one way, so you have about 245km left. You warm up the car 30 minutes beforehand, with 4% loss, so about 16km, so you will be down to about 229km.
As you can tell, even if you become super inefficient on the way home, have to do a large detour, count for more losses through the day in the cold etc, you still have a lot of range left, as long as you remember to charge your battery overnight at home.
So, IMHO, get whatever battery you can faster. Won't make too much of a difference.
