I can't work out why you would want such a wide tyre for your winter set. If you want grip in snow and ice you don't want wide tyres. Also why would you want super light wheels. When winter comes so does terrible road conditions and pot holes or certainly in the UK. Thus you want the strongest wheels you can get. I buy the arguments for the summer, but for winter your car will handle worse.
I would go with what BMW designed in terms of widths for winter running. They did a lot of testing to work out what worked best.
Out of interest my winter set is 225/45/17
E90 330i SE Auto Graphite Grey Metalic