Winter tyres for b7

[JohnyRocket]

Hi guys,
This morning I had the sledge like experience with my 2.0 SE TDI saloon on a small patch of ice. No surprise as it rolls on the (wide) set of ContiSports 3 which are rubbish on slippery. Hence, I'd like to get an additional set of winter tyres and steel wheels. Has anyone tried "downgrading" to 215/55 R16 and do you actually have/know the rim size for it? Also, any experience to share with winter tyres maybe?
Cheers...