Well, don't feel bad if it's difficult to find something in Tenafly or Demarest. Because of the schools there, prices stay high & homes move fast.

But the schools are great all the way up to the NYS border. Look up towns in Northern Bergen County (ie, Cresskill, Haworth, Harrington Park, Northvale, Norwood, Wyckoff, Ridgewood, Emerson, Park Ridge, River Vale, Westwood, Hillsdale). They're all very commutable. Some towns have commuter trains & they all have buses if you don't want to drive (but most people commuting in-state do drive.)

Good luck.