*puts on researcher hat* For anyone wanting an idea of where Harry is in the city, a friend of mine has helped me get this map properly centred:
Click here for map. Untick the "events" box to get rid of those annoying little bubbles. I can't get them to not be there in the URL. The top is North Avenue, and if you pull down until you see Roosevelt, that's he bottom of the Loop. Harry's place is somewhere between North Street and the Loop, and much of this stuff is within walking range for a rangy wizard whose car doesn't like to work.