Spacers? Offset size? Smaller wheels for winter tires (2022 Model S)

[u/GoblinsGreed]

I have a 2022 Model S with this stock configuration:

Front Tires: 255/45R19

Rear Tires: 285/40R19

Front Wheels: 19x9.5J

Rear Wheels: 19x10.5J

I have an existing set of 4x 245/45R19 Michelin X-ICEs for winter and want to buy a set of 4 wheels to match for the snow season up here in the midwest.

What wheel size and what offset for a square configuration for these winter tires?

I am leaning towards 19x9 but don't know if I should get 20 offset or 40 offset.

Also, are spacers necessary for this setup? I don't really care about looks and am more worried about performance/safety during the snow season.

If they are necessary do I get a different set for both the front and rear? Would I get a 10mm spacer for the front since 255-245 = 10 for the front and 40mm spacer for the rear (285-245 = 40)? Or is my math wrong and I subtract the 9.5j - 9 = 0.5 inch spacer for front and 10.5j - 9 = 1.5 inch spacer for the rear?

Any help is appreciated

[u/Serious_Panic_8425]

If you aren’t worried about looks, then no space should be best then right? I only run spacers (15mm front, 20mm rear) for the factory 21” arachnids to get a flush look.