I've been using winter tyres for some years on both my cars, started when I went to Denmark (where our daughter lives) as they are compulsory between Nov and March there.
As I live in the south, we don't often get a lot of snow, but have to deal with low temperature and damp roads, so I have opted for the same size wheels, 16" for the Touran and 18" for the Golf.
I bought secondhand OEM wheels for the Touran and found a set of BBS (Audi) wheels for the Golf. Both are fitted with Nokian tyres, which are really good and reasonably priced. Fortunate to have space to store two additional sets and the advantage is the other than the cost of the wheels, your other tyres last longer.