I just went through this on my 2023 MSP. Spent hours upon hours reading, researching... in the end I pieced together the 19" set that Tesla was offering (but continually out of stock) on their website.. albeit considerably more money.
I found a set of new 19" Tempest wheels (staggered) on eBay that had been powder coated gloss black, picked up a set of used TP sensors also on eBay, and my local tire store was able to get me the Pirelli P Zero Winter Tesla OEM spec in the staggered sizes. Overall I'm very happy with the ride and appearance. As many have said the car does seem to ride better on the 19" setup vs the 21" setup.
**Full disclosure we have not had much snow here in Central Michigan since Christmas, so I have not had a chance to test the actual snow/winter capabilities. Will update soon, as it is snowing as I post this.
Wheels:
Front: 2x 19X9.5J ET40 Tesla Tempest Wheels (powder coated gloss black)
Rear: 2x 19X10.5J ET40 Tesla Tempest Wheels (powder coated gloss black)
Tires:
Front (2) 255/45R19 104V XL T0 TESLA PNCS ELECT P ZERO™ WINTER
Rear (2) 285/40R19 107V XL T0 TESLA PNCS ELECT P ZERO™ WINTER
Misc: 4 Used BLE tire pressure sensors
note: I had to really mess with the contrast settings to get the tires to show up in this pic.
And here is a closeup of one: