This is basically what bombers all do. Flying the B29 at altitude you have to line up from far out. If you wait until you can see the base you cannot get the bomb sight onto the target withou messing up calibration. So most people get used to using straight edges (scales, rulers, index cards) to project the center of the users airplane forward two sectors. It isnt precise but its better than adjusting later.
The protractor idea would be a big help but for the most part its for town killers in sub-orbit.