I grew up in rural WI and (IME) that means absolutely
nothing as far as being a 'survivalist' or 'living off the grid.' And if JY had never even spent a night in the woods before then (
LINK), I'm not buying that a few books would give him the practical know-how or instinct to be able to survive on his own long-term.
I
really hope that they're digging deep into JY's online activity and considering the possibility that he may have planned this out with someone whom he may have thought he could trust. The longer this goes on with no sign of him, the more likely it seems that someone else was involved.
(
LINK to a case from last year in which a 13yo boy was kidnapped by a man he met online - they had made 'camping out somewhere off the grid' plans as well, IIRC)