Of course, nobody knows what you'll find until you rip it open. And yes, chasing rot under the fridge / cabinets may prove challenging. Maybe you decide (once you've had a good look) that you replace all of the subfloor right up to the cabinets and don't worry too much about what's under them anyway, as long as you've dealt with all of the significantly structural rot. Or maybe that's not good enough, and you figure out how to pull the cabinets and do it "right", stem to stern.
We are all wired different in our heads - I just replaced the roof on my MH. How I dealt with the unknown was asking myself "what's the worst thing that could happen?" and then going from there with my game plan. Once I had a "plan B" I figured I was good to give it a shot. Also, don't let the "perfect" be the enemy of the good (enough). Not to say do a crappy job - just to make judgment calls that will get you to a decent result, given your time, money, and the value of the end product. It's a balancing act, in my opinion.
Steve & Carol
2000 Jayco 3230K Designer