Bike Route 17 is certainly a challenge in areas. I have ridden most of it east of Binghampton as day rides . As for stealth camping. just keep in mind most land in NYS is privately owned and even simple trespass in NY on posted property is a misdemeanor meaning you can arrested and jailed on the spot if the landowner is pissed enough. As for free camping most parks that allow it will charge. some state forests and many DEC game management areas do allow primitive camping.