It's just me--but, if I owned a 1M, it wouldn't be out during winter. My humble 128 is tucked away December-February. My Focus takes care of winter, with the Blizzaks on.
That was my plan all along. Your plan may be different, but the thought of a 1M pulling through snow, slush, and slop, along with the attendant washing issues was never on my radar. But, hey, that's me. I'm sure that the above snow tire plans would work out for you, given the 1M's M3 suspension heritage.
Drillslinger--Here's hoping BMW brings the 1M to military sales. Can't think of anyone who would deserve such a sweet ride any more than you!