Hmm, twenty one miles in a blizzard in Chicago...

Unless there's some public transportation service capable of navigating in the blizzard, then I would suggest staying put till the blizzard is done at the least. By the time you could make alternate transport arrangements you would probably have taken as long anyways. If it were dire for me to get home, I'd probably jack up one of the municipal snow plows and pay the consequences later. Not much of an alternative, not because of the impending jail time later, but because of excessive risk of traveling in very adverse circumstances. If the snow plows aren't running because the weather's too much, then travelling would become pretty pointless.