I carry a small pack of self-adhesive patches, a small pump that mounts next to my bottle cage, and a 3-set of tire levers that nest together. Easily carried in a small underseat pack.
This setup has saved the day more than once. The patches don't work so well if the problem is around the stem which happened to an old tube on my wife's bike, but worked good enough to get us back to the civilized world!