The furniture can perhaps be partially disassembled for removal?
I doubt that they put the furnishings in and then put the shell together.
I found that in my Scamp
all of the floor rot came from the inside where water leaking in puddles and remained for a while.
To prevent this I installed new 3/4" exterior plywood fiberglassed with cloth and epoxy resin both sides and edges as well.
I used epoxy because it is more water penetration resistance and bonds well to the wood. I then fiberglassed the entire shell contact with the floor with strips of cloth and epoxy resin to make the floor a sealed monolithic barrier to water getting into the wood of there are any leaks
from the outside or the utilities.
It is a true PITA to remove everything and removing and replacing the floor and I didn't want the rot to happen again.
Besides if the water caused a problem the smell would drive SWMBO crazy and be the end of camping in the FrankenScamp.
I recently had a water pump leak in the potable water system and ended up with an inch or so pf water in the sealed compartment under one of the beds. (I was checking the system for leaks
with a new check valve before the pump).
No water ran from under the bed and the floor was basically a second tank.
No water on bare wood.
Perhaps not a good idea if there is a leak not found, but the floor is SEALED.
I pulled the drain line for the tank out to drain the compartment and died it with some paper towels.
The problem which caused both the pressure bleed down causing cycling of the pump and the leak when the check valve was installed was loose bolts holding the pump head together and to the motor.