Volvo V70 - Winter Tyres - Economograd

I am taking delivery of a new V70 with 225/50 R17W tyres on 17" rims in December. I want to buy a set of extra rims to fit with winter tyres, but alloys are prohibitively expensive so am contemplating buying steel rims. If I buy 16" rims, what size tyres do I need and would the new combination affect driving characteristics/handling? All advice appreciated.

Volvo V70 - Winter Tyres - nortones2

You might try www.mytyres.co.uk/Cold_Weather_Tyres.html - they have packages of steel rims with winter/cold weather tyres. They also claim to match the car reg with the correct tyre. No conection except buying 4 Nokians last winter.