Why all the snow hate... SNOW IS AWESOME...
A. Snow Tires are a MUST on a RWD BMW. Blizzaks (LM-22) or Hakkas are the way to go.
B. Steel Rims work just fine if you don't care about what they look like for 4 months. Otherwise hit up tire rack for some 17" non stag with snows...
C. Like anywhere if you are on bumpy roads you risk bends in your 19's with low pros. Just gotta learn the area. In the city, drive slow. Highways are fine.
D. Lowered car is the same anywhere to. Gotta watch out.
I ran an E36 328is on Billy's and H+R's with Mtech and 17's for the winter - no big deal.
Also after a storm and the roads dry wash your car. Pressure wash with attention to the undercarriage.
Also used to run an E46 with M-tech, 18's, on PSS9's. Just gotta watch out for dips. You can keep a car pristine if you are careful in bad places and wash it religiously.
Or get an E30 for the winter...