RS6 C7 winter tyre advice needed

[LRB23]

I’m looking into options for winter tyres and would like some feedback.

Option 1
Purchase a winter tyre and swap over my summer tyre. I have found these online from Gripmax in the same size configuration I have currently (285 30 R21”) for a good price of £190 per tyre. As I will only be using them from December - April these seem like a bargain. The speed index is Cat V (up to 150mph), which for me personally is fine as I don’t plan to drive fast in the snowy mountains.
Any reason not to get them?

https://www.mytyres.co.uk/rshop/tyre/Gr ... V/R-349227

Option 2
Purchase a new set of aftermarket alloys and tyres. Either step down a size and save money and possibly improve ride quality or find another set of 21’s.

[HPsauce]

A separate set of winter wheels at a smaller size is the way I've always gone.
Get the smallest (cheapest?) wheels that fit over the brakes and deeper profile tyres so that the rolling radius is the same and speedo unaffected.
As for tyres I've only ever used premium brand winter tyres, it doesn't seem to matter which brand exactly as they're all much the same.
My S8 is currently on 18" Sottozeros (20" PS4s's in summer), the other car nowadays has all-season Michelins, it's predecessor had two sets like the Audi.