I go to the University of Maryland University College and it is online very "correctly" accredited and award-winning. My professors are often in other states or parts of the world!
http://www.umuc.edu/faculty/employment/emp_home.html More and more colleges have online positions and there's online tutoring, etc.
http://www.tutor.com/ I don't see any reason you couldn't aspire to get your doctorate and teach online. Even if it proves to be not possible in the future, I think it's a fine goal to persue as long as you can? I'm getting too "old" but I'm working on a related goal anyway, because I want to. Why not; what else are you doing instead?