You have to look at colleges individually, as each college sets its own policies.
ED is essentially a contract. By applying ED the student promises to go there if accepted. If you look at stats on college sites you'll see that only about 1% of students accepted ED do not matriculate.
So you could look at a D2 school or any other school, but that would be as plan B should ED not work out.
Decent summary here: http://professionals.collegebo...e/applications/early