I just got new winter wheels for the 35i. I ordered them on TireRack.com and went for the Anthracite Rial Salerno in 17" with LM50 Blizzak in 225/60R17.
They don't look as good as my 19" but I think it still looks fine. I am surprised by how it improved the comfort of the car and how quieter it is. Obviously the handling is degraded but it is still fine.
Total cost was $1500, the wheels arrived the next day and I can confirm 17" wheels fit on the 35i.
If only it could snow now...