In terms of college athletics at the highest level in the northeast we are basically talking five states, Pennsylvania, New York, Massachusetts, New Jersey, and Connecticut.
In terms of private school power (regardless of athletics) within the state for the latter two it's Princeton then Rutgers and Yale then UConn. Since the Ivies made a conscious decision to step back on truly competing in college athletics at the highest level a long time ago, Rutgers and UConn became northeastern equivalents of flagship universities, although in areas where pro sports still rule over college sports.
In Pennsylvania it's three privates in terms of academics Penn, Carnegie Mellon, and Lehigh and two quasi-publics PSU and Pitt. Again, similar to New Jersey and Connecticut although expanded out to 5 colleges rather than simply two.
Only in New York and Massachusetts do private schools dominate the academic scene to a much greater extent. In Massachusetts it's Harvard, MIT, Boston University, Tufts, Boston College, and Brandeis before UMass. And in New York it's Columbia, Cornell, NYU, University of Rochester, and Syracuse before any of the SUNYs. And when the Ivies stepped back from college athletics at the highest level Boston College and Syracuse were the ones that came to the forefront.
Would it be impossible for either UMass or UB/SB to overtake BC and SU respectively as the college athletics standard bearer in their respective states? No, but the chances of it happening are virtually nil. Especially with the divide that currently exists in college athletics now.
Cheers,
Neil