Yes I agree that the Pex pipe is sooooo much better. I remolded my neighbors master bath last year in her trailer and use Pex Pipe. Only the lines to her shower froze last week but thawed out on their own with the warmer weather. Like you, I have a crimper and clamps just in case. LOLNewer RV's tend to use PEX line for plumbing. While there is still a chance of PEX "fittings" failing, the line itself will expand when frozen and then return to normal when it warms up and thaws. Almost 10 years now of living full time in our fifth wheel, and in all that time there has only been two fittings fail, and that wasn't even because of freezing. I now have a PEX crimping tool and clamps in the RV.
Living in an RV is fun...
...in more ways than one.