I don't travel out of state. Just a long commute here in NC!
Most cops & Highway Patrol officers here are good about folks carrying weapons in their car, so long as you let them know up front you have one. I had a HP officer pull me over for speeding a few weeks ago (I was listening to a Braves game and not paying attention). When he came up to the car, I had the window down & hands on the wheel & told him I had the 9mm on the seat beside me so he wouldn't see it and think I was going for it when I got the registration out of the glovebox. Anyway, he asked about a CC permit (which I don't have) and I told him I didn't have one, which is why it was on the seat and not in the glovebox. He said "OK, slow it down & have a nice day!". First time I have been let out of a ticket in my life!
Anyway, he, like most cops I know, was fine with a law-abiding citizen having a gun. He knew I wasn't some gang-banger or druggie and he knew where the gun was, so everything was fine.
I need to look into the law mentioned RE: the original topic of this thread. I think the homeowner was well within his rights to give the perp a permanent nap. If the guy came towards him, even outside of his house, I think he was within his rights to shoot. Not 100% sure about that, though.
Illinois is a sad state, completely run by democrats, there's no concealed carry law here whatsoever. That makes my state one of only 4 in the U.S. that doesn't have some form of the law.
My 68 year old brother rides a motorcycle a lot and goes to different states. He told me that he carries a loaded gun in his saddle bag. He didn't even know that it was illegal in Illinois and probably other states where he travels.