Over the years, at the side of various roads, I have broken beads and patched inner tubes, rebuilt alternators, replaced the Ford power steering pressure hose, used the engine fuel pump to pump water out of the bottom of my fuel tank into a glass jar, swapped out the pumpkin in a Ford 9" rear end, bolted a rear axle back onto an old VW Rabbit, and probably a bunch of things I've forgotten.
It's surprising how much you can do with how little when help is a hundred miles away. Nowadays I try to take care of problems at home, before I go, rather than hoping it'll last. No more bald tires, no more running belts until they break, and so on. I still carry parts and tools with me, just in case. For example, on my Powerstroke, I carry a power steering pressure hose, a serpentine belt, light bulbs, a cam position sensor, and stuff to deal with broken wires, because the wiring harness is ****.