Star, on a campus that is supportive of Greek Life, with a large interest group, you may have an opportunity to colonize a new sorority, but having the other sororities on campus at or near ceiling should only sell that point to the Greek Life people. On my campus, three sororities are near death, and they're letting a new national take on a local instead of merging with an already existing national. I think it's truly worth a shot.
As for NPHC groups, I don't know nearly enough to claim knowledge, but a friend of mine that was in school with me pledged A Phi A at another school, with the intention of starting a new chapter at my school once he learned the ropes. At this point, I don't think that's happened. But he had to go two hours every night to pledge events and all of his fraternity stuff. Mind you, in the end, he had made a great accomplishment and we were really proud of him
