Who can point me to a  NJ or Federal statute that covers firearms in hotels, campgrounds or other locations in NJ one might temporarily reside? Would this be up to the private property owner? What about out of state travelers stopping for the night with NJ legal firearms?

You may want to read up on the Gregg Revell case.

Basically the judge said he was in violation of the law when his weapon and ammo was readily accessible in the hotel room even though he had no other options..

I'm pretty sure New Jersey law makes no exception for temporary residences.  Some other states define "abode" more widely (hotel, RV,  etc)but New Jersey does not.

 

The Firearms owners protection act doesn't really cover stops of that length, at least i wouldn't chance a stop like that in a state like this one.

I presume that a hotel room isn't covered as a "reasonable" deviation from the point to point nonsense that we currently live under, but it would be interesting if anyone has a link to legislation that states otherwise.

I also presume that a carry permit would be sufficient to cover staying in a hotel/camper with your carry gun, but not with any others you may be bringing along.

FOPA would protect you if you are travelling through the state, even if you stop, provided you maintain the transportation rules. 

You're entering some murkery scenario here referring to these places as a temporary residence.. I would say, unless you have the powers of a property owner or tenant, it would not be considered a residence/home/domicile. The courts would 100% consider you a guest of the property, and you have zero options unless otherwise own a permit to carry, or a FPID for rifles.