Still learning here, but my G26 which carries 10+1 is usually sitting in my Crossbread Supertuck. I ALWAYS carry a spare G19 mag which holds 15. Usually the spare is in a cargo pocket and not a problem. Once its cooler, it'll go in an inside coat pocket I think. Hopefully, neither will ever need to be used, but, I too, would hate to think I may need another mag, and not have one!
I'm considering having another mag or two in my car, G17's=33 rounds!, which may be available to restock in a major incident. Just a thought.
Take care all, Pete D.---