I was speaking more-or-less theoretically. I wouldn't fly to NJ with a firearm (wouldn't go there, period). And by association, any state remotely close to it (you might get diverted to NJ!) I have flown with firearms to Texas, which is totally a safe zone. And into Nashville, which should be safe ... unlikely that you'd be diverted to an unsafe zone as far away from Nashville as Chicago or Washington, D.C.

For the most part, if you steer well clear of NJ (the entire state), NY City, CA (the entire state), Chicago and Washington, D.C. you should be fine even if reasonably diverted. I think Hawaii might be in there also, which is a terrible shame. Better to just avoid a multi-state zone around these places than to take chances accidentally ending up in one and risking prison for normal everyday activities done elsewhere. It's a shame that these places have effectively black-listed entire zones of the US for travel, but they have. They're all pretty much collapsing in on themselves (except Hawaii), so maybe, someday, I'll be able to travel to the black-listed zones after they finish collapsing.