I went to Tire Rack and ordered winter tires, wheels and TPMS Mounted and balanced. I have the 18” staggered wheel/tires on my 135i for summer but I got 17” wheels and 225/45/17 tires all around for winter. The winter tires ware really quickly on dry pavement so you can rotate them. It sounds like I am a little more aggressive driver than you and I think the winter setup is fine. I have a couple floor jacks and air compressor and change back to summer if no snow is forecast for a week. I can change all four wheels in 20 minutes.
2015 M235i - Estoril Blue - 6 speed - Black Lather - Cold Weather Package - Premium Package - Harmon/Kardon Premium sound