Upstate wouldnt have to be a city at all. Could be a town, hamlet village, unincorporated land, state park. Archer was young enough to have been around while earth was still rebuilding in theory.
Upstate itself is also a very general location for the state. It’s most commonly used by people from the NYC metro area to refer to pretty much anything north of the bronx. This means upstate could in theory refer to anything from Westchester or Rockland county, to Watertown, to Niagara falls(though dont tell a western new yorker theyre from upstate they’ll throw a fit).