Hi, We live in the same city commute pratically the same distance. I commute every day(yes, including the last week or so in the - 30's). I haven't missed a day at work either through sickness or weather in almost 5 years. I can see your companies policy, what if a cager or transit commuter want's the same privelage you seek? If they allow you to stay home then potentially there's nobody in the office during a cold day. Be thankful for the underground parking, a shower and a gym pass.
Buy some extra cold weather gear and get on your bike.

Not to be too much of a jerk, but if you were really a hardcore commuter you'd never had started this thread.

'Rasher