Z4 also in winter

Hello, think about the purchase of a young used Z4. Next weekend I get the 2.5 to the rehearsal. Ride at the moment a 320d, with which I got great through the last winter. Must drive in every day 50 KM to Munich, i.e. even if the snow has fallen in mass again. Who has experience with the Z4 in extreme road conditions? Problemless like the 320d or more difficulties due to the lower weight, etc? Is there also a St4 for the Z4 andheizung (carport instead of garage)? Thank you for your help