Duct tape makes a great tire boot, as do dollar bills. Replace your cables, tires and tubes before you go and the chance of a truly catastrophic failure becomes nearly zero, although spare tubes and a patch kit are still a good idea. Fiberfix spokes will fix a broken spoke on either side of either wheel. If your tubes have Presta valves, a Presta to Schrader adapter will let you top off the tire at any gas station.
True your wheels and check spoke tension with a tensiometer before you go and you will greatly reduce the chance of spoke breakage.