Lol - I just ordered the same thing (I got the TST style). I've been searching all over for other options and this seems the best bang for the buck. I didn't want to buy a set of rims so I tried to find 21" winter tires. I talked to Michelin and the 285/30/r21 Alpins would be close enough in size to the stock rear tires to work but are discontinued. Other brands have winter tires in the 255/35/r21 OR the 275/35/r21 but not both.
I tried to get Tesla to give me a quote on 4 Gemini rims but they are backed up and the voicemail is full etc. Even then, I've heard getting TPMS sensors from Tesla takes some time and other places like Tire Rack don't have them so they can't sell me a complete set ready to mount. If I buy individual wheels, tires, and sensors, I get hit with shipping and still have to pay installation since I can't mount / balance them.
I thought about buying take-offs from other people but I don't want to pay $300-$400 for shipping and get an all-season tire since the reason I'm doing this is to get a cold weather tire.
Finally, when I looked at Martian, Ohm, Unplugged Performance, and others, they all sell NICE wheels. I don't want to pay for premium wheels for a set of snow tires. Normally, you put your snow tires on your crappy OEM wheels and buy a nice setup for summer but I LOVE the Uber Turbines so I'm trying to find the most cost effective winter setup and it looks like T-Sportline is it! The whole package will arrive on my doorstep ready to install for $3150!