Fire up Google Earth and go to your house bookmark. (I know you have one.) Turn off all markers smaller than county lines. At what virtual altitude can you locate your house well enough to hit it with, say, a 100-foot Circle of Destruction?
No cheating by starting zoomed in and moving back. You have to be able to locate and zero in on your spot without derived clues from a close-up. (You’ll figure out what that means when you try it.)
I can spot the intersection pointing at my house from about 35 miles.