DBag84 (interesting name by the way) DEFINITELY buy dedicated winter tires for this beast and you'll see a difference.
BUT do NOT buy snow tires. we need an ICE tire around here.
whats the difference? SIPES. you can get sipes put into a normal new winter tire, but a lot of winter tires already have them from factory and are considered an ice tire as the ruber sipes open up and act as a suction cup (more or less) to the ground instead of just a rubber block driving over ice/snow/cold ground. Yes these tires may wear a bit faster, but nothing you'd really care about once you start driving with this confidence level. you can justify the fact that you will only get 3 seasons instead of 4 out of an ice tire.
Nokian Hakaplettiaaergaerga (seriously does anyone know how to actually spell this) are amazing tires and well worth the $1400 from Kal tire.
Nokian AW tires are also sensations from friend reviews as well as internet reviews.
OR buy some used ice tires from Kijiji. great tires and wheels always on there. some on there NOW to be honest.
look for a nice square set-up of 18"x8.5". the tires available for these wheels are endless.
when looking for tires, do not type in "BMW", type in 255 55 18 and you'll see a million sales on Kijiji and then choose a good set of ICE tires.
next set (next year) wil be the Nokian Hak... STUDDED. they make a vehicle perform on ice like nothing else.

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I swear, my cars are like a girlfriend.
Sometimes its a rough ride, sometimes its smooth motorin'.
Sometimes she doesnt like how i treat her and sometimes i dont like how she behaves.
BUT at the end of the day, she loves it when I am inside her.

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'91 850i
'05 X5 4.4i
'09 Clubman S