I will discuss this with the electrician on Sunday. Do you know how fast the SR+ will charge on Level 1 15A?
Also, apparently for the 240V I need to install a DCC-9 panel and that's minimum $1120 CAD. Do you need that for Level 1 ?
About 5 miles added per hour of charging. Since you "work from home 24/7" this is a viable option. Charging rate only matters if your commute or daily consumption is high. You can charge from 10% to 90% in 2 days if it's just sitting. 240V is nice, but at that price and with supercharger 5km away, I'd skip that. Adding the 120V run is going to be a lot cheaper and easier, and if it's even $800, that's still a huge savings over your BMW lease. I'm not sure, but I'd doubt you'd need a DCC-9 panel for a 120V circuit. Electrician will know for sure.
Charging wise, I think this is viable for you, even as you can't easily install outlets. The car is super efficient now, and even if you let it sit without charging, the vampire drain is about 1 mile per day. So you could for example stop by supercharger whenever coming home, charge to 90%, and just let it sit until next you go out. You'll still have 80% or better in every case.
I can charge at home on 120V, and this is what I do. I've got a supercharger about 5km away as well, and I've been using it currently because I got free miles from a referral. Before that, I would charge in garage of 120V, and always have a 90% car, because I don't have a daily trip that needs faster charging. The way to think about charging is 'how fast does it need to be?' If you are on a road trip, then it sort of matters, because a supercharger can fill up in 30m or so. That's actually a little to quick for me- I typically will want to take an hour to eat while it charges. It's a different mindset when you drive an EV. You can charge up in weird places, like free parking if you have an EV. If you don't think of it as a gas-tank, you just charge whenever, and get whatever is convenient.
I'm less sure about the question of AWD for the snow, because I haven't driven this in snow. But a rear wheel drive car that is super heavy and well balanced should be pretty damn good in snow. I grew up in CO and drove a VW bug in the snow constantly, and it was fabulous.
Would be worth checking on YouTube for how much the cold impacts range. Brand new car will have heat pump, so it will be less impact now. Given how little you drive, the real question is when you drive, do you need extra range or not?
Relative to letting a car sit around- I drive very little as well, work from home even before covid. EV is far better in this sitting around scenario. ICE cars don't like to sit. Probably irrelevant for a new lease, but my old cars got cranky.