it's true that american flyers @ ISP has been closed, for some time now i believe.
the only other schools at ISP is midisland air, unless someone knows of any others?
FRG has quite a few. nassau flyers, lfacademy, air east?, suny frg, to name a few...i'm sure there are a couple of others at frg.
there are quite a few in nj as well. many small airports that have flight schools >>>> princeton, linden, caldwell (i think the dpe marcus buttikofer has a school there), morristown, lincoln park, the flying w, red lion, allaire, etc.
just look on the ny sectional, find an airport and google it. you should get the flight schools that are located at that airport. or look in your afd for some info as well.
white plains-HPN....i believe panarama flight academy is still there.
i'm sure they're all hurting for instructors now....and will be for quite some time.
good luck