Lots of people drink(among other things) and have carry permits.
There shouldn’t even be a such thing as a “carry permit”. If you can legally own the dammed gun, you should be able to carry it in any way you please, where you are permitted to do so. What you do in the way drugs or alcohol is irrelevant.
If you’re impaired and kill someone, you’ll still go to prison, if deadly force wasn’t warranted. This is just another case of layers of laws on top of laws. It’s just stupid.
Some people can’t do without nannyguv holding their hands, even here on FR.
My copy of the Constitution doesn't seem to mention locations where the right can be infringed upon.