Meh, small spuds. I have been remodeling and into different spaces for years. Replacing a few panels of flooring and pulling the wet insulation is easy. I would assume that pulling the under belly covering is one of the remediation steps. You want to make sure that any floor framing and flooring sheets are dry. Just from your descriptions, maybe it's possible to cut the fabric at the wall joint where it is wrapped, save the material, and reinstall it when done. Since this RV is parked, you won't have to worry about road grime and water entering while you're working on it.
How you schedule the completion of your project is up to you but I'd give it some thought and see how and what you need to transport to make it all better than new. In my work truck, I haul a complete set of tools and various hardware/fasteners so my workshop travels with me. If you're short on tools to make the job go easy and fast, seek out a friend or guy that has them for loan. Maybe you can even talk him into helping. If I was closer...
Here are a few things I'd plan to do: Find where the water is coming from. Remove bad flooring sheets. Remove any wet or compacted insulation. Treat wet spaces in floor framing with bleach/water. Dry floor and framing with fans. Install foam board in place of spun fiberglass. Replace OSB with floor rated plywood. Inspect and tighten all plumbing bits.
I'd very much suggest to do the interior pressure test. For me, nothing would be worse than repairing a floor only to find that there are other leak entrances, undiscovered. If I had to rent a blower to do it, I would.
Good luck with the floor. It will go quickly, once you start.