BRZ as my only car through a lake effect winter, what actually makes that workable?

Numbers from my own winter setup, because everyone gives vibes on this question. Narrower is better: I dropped from the stock width to the narrowest winter size that the manufacturer lists as acceptable, on steel wheels, and it cut through slush instead of floating on it. Steels rather than alloys because you will kerb them on invisible snow banks and you will not care. Set them a couple of psi higher than you would in summer to compensate for the cold, and check monthly because they will drop again.

The other spend that mattered more than I expected was a proper snow brush with a telescoping handle and a bag of grit in the boot for weight and traction. Neither is glamorous and both got used weekly.

I ran mine on all seasons for one winter to save money and it was the single worst driving of my life. Constant traction light, could not get out of a flat junction without slipping, and I put a wheel into a snowbank at low speed avoiding someone. Nothing expensive broke and my pride did not recover for a while. The winters I bought the following November cost less than what I had convinced myself I was saving, and the car became completely unremarkable to drive.

Ran a light rear drive coupe through four winters. On proper winters it is genuinely fine on any road that has been plowed, and the low weight and honest steering make it easier to catch than something tall and numb. What ends the fun is depth, not grip. The moment the snow is deeper than your ground clearance you are a plow, and a plow with no weight over the drive wheels goes nowhere.

I think the ground clearance worry is overstated for the commute you describe. If your one unplowed street gets cleared by afternoon, you are dealing with it once each way on a handful of days a year, and the real question is whether you can leave twenty minutes later on those mornings. What I would not do is park it on the street where a plow can bury it. I ran a low car for six winters in a snow belt and I got stuck three times total, all three in a parking lot rather than on a road.

Practical things nobody mentions about a low rear drive car left outside: the boot lid seal freezes shut, the doors freeze if you wash it and do not dry the seals, and heated seats matter more than heated grips ever did on a bike because the cabin takes a while to warm. Silicone grease on the door seals in November is a two minute job that saves you a lot of swearing in January.

Winters and a bag of grit in the boot, and it is a car. Sell it because you dislike it, not because of snow.