My husband wears through socks so fast, I have given up on keeping up with the mending. Darning socks is a rare skill nowadays. :)
We have a friend who CosPlays and carries a Housewife Kit to conventions in case of wardrobe malfunctions.
It has been very handy to have a repair kit available when traveling as well. Mine has a few needles, a few safety pins, and 3 colors of thread.
You are smart to be so prepared. When I am at belly dance functions the best I do is carry safety pins, a costuming essential. Have you tried darning? I saw a couple of youtube videos that got me interested. But honestly, one more thing...