In my completely NOT A PROFESSIONAL opinion, this would mean that you would be able to stop for the night in a state that doesn't let you carry the weapon but wherein also you may possess it. The justification is that if you are allowed to possess the firearm within the hotel room, or in the home of the person you're visiting en route that night, then the statute applies to get you into that room and out of that room.
Tell that to the guy who was arrested at the New Jersey Airport because he had to stay overnight when his flight was cancelled.