Broken water pipe(s) repair or replace

Our 1999 Pace Arrow Vision is showing aging signs. I probably contributed to it by leaving some water in a low spot of the water pipes when I "winterized" last season. Now leaks. And the piping is CPVC and has gotten brittle over 20 years and hard to repair. One leak was repaired and on testing another leak appeared further down the pipe. Leaks are in an almost impenetrable location under furnace and refrigerator. Also near electrical panel and many wiring junctions, circuit boards etc. I will need a plumbing diagram from Fleetwood and hopefully they will comply. Has anyone had experience with this type of problem? I am considering replacing as much piping as possible with PEX or something similar. A huge problem is the crossover of piping from the left to right side of coach. This originates in a tightly confined space under the floor and ends above the floor at the refrigerator area. My body won't it in there. I would love to hear others' similar experiences.