Snow removal is a constant challenge in major cities. Sometimes it gets dumped into a nearby river, or gets trucked to an unused or underutilized parking lot or similar space.

If you're so snowed in that your door won't open (which is unlikely, but possible), you can open a window and climb out that way. But inward-opening doors are a ready-made solution to this, as you can always open the door inward and then start shoveling from the landing.