While I realize that New York is not a part of New England proper, never has been a part of New England, and never will be a part of New England...the city itself (and surrounding area, and Long Island) have historically been more closely aligned with New England economically and politically, as far as I can tell.
In a time line where New England seceded for whatever reason (Burr?) what are the odds of New York City - not the whole State! - going with them? Educate me!