Some great advice in here, especially the "take half the gear and twice the money."
While I've never done a motorcycle tour with cameras, I've done a bicycle tour (similar requirements/concerns). I second bringing the most durable/inexpensive kit that you are 100% confident will give you the image quality you need (noting the difference between this and want).
The M2 will be a stellar camera, but be exceptionally wary of the vibrations, as in my experience they affect RFs more than SLRs. I took my M4-P on a cross-country bike trip across Korea, with an FG-20 as backup. The vibrations ended up working loose the retaining ring on the front element of the lens on my M4-P, and I only noticed when the element came off fully and was rattling around inside the lenscap on the final day (meaning that 90% of my shots were out of focus, which is effectively impossible to do via user-error when using a 21mm wide-angle at F8...). Thankfully, the single roll I shot with the FG-20 "just in case" yielded the 4-5 keepers that I'm quite pleased with.
I realize that this anecdote isn't actually about the RF mechanism, but it's a known weak-point for RFs and that they're less tolerant of impacts (generally these are terminal regardless of camera-type), but also high-frequency vibrations that are common with bicycle/motorcycle touring.
Focus less on the gear and more on making sure your equipment won't let you down (reliability is king), and choosing a great route. In general, the pictures you look at 10-20 years from now will not remind you of "wow I'm so glad I brought my Hasselblad and not my Rolleiflex," unless something breaks or malfunctions, and you will forever be angry and filled with regret about your gear letting you down. I love my M4-P and the 21mm lens, but the thing that I will never forget about that trip is how the lens ring unscrewed itself, little by little.