Well, seeing as I work in downtown Chicago and home is nearly 35 miles away, this is a scenario I've considered.

1st choice: Metra (and it would take something awfully big to dirupt that, but it's certainly possible).
2nd choice: car (but traffic can be truly terrible).

I'd take it in stages taking the bus and walking -- I carry transit maps with me and I grew up here, so I'm pretty familiar with what areas to avoid and where the bridges across the rivers are.

If there was a blizzard -- nuh uh, I have plenty of food, a change of clothing, and my yoga mat in my office (in addition to the multi-band radio, etc.) -- I'm staying put. If I had already left the office and couldn't get back in, there are warming centers run by the city -- a lot better than nothing.

My other major option is to hike a few miles north along LSD to my aunt's condo. <img src="/images/graemlins/smile.gif" alt="" />

Thanks for posing the question -- these are great exercises!