Very interesting question and not something I imagine anybody could give a definitive answer to. Depends on the conditions in my opinion, however I believe that model has traction control known as Drive Stability Control on my car which should help you out in slippy conditions although I have no experience in snow living in the Middle East. BMW are pretty good with the safety aspects and to put some weight in the back of a modern car seems ridiculous to me, I would leave it to other snow-experienced board members, just my twopence worth.
WillM5AD