This’ll be an anathema to @Alison – but I do carry a spare infusion set, etc., with me. I keep it in a separate pencil case from my BG meter and the stuff I sue all the time and I just dump it in the bottom of whichever manbag I’m currently using.
It was really useful the other day when I had to change my set at work – I just got out the spare set and away I went. I also have a small stockpile of sets in my desk at work.