Huntindog writes "All of your concerns would be much MORE serious if the unit was to be occupied by sleeping people if the sky were to fall. "
:h
Honestly, not sure as to what your getting at...
I never said that the "sky is falling" and the RV WILL burn up...
To put it another way, if YOU ARE PRESENT and the furnace malfunctions AND YOU HAVE working smoke detectors you most likely will be woke up and leave the RV(no falling sky just the reality in life that "stuff" does indeed happen).
If you are lucky you just might catch the malfunction BEFORE any fire or damage happens.
When you are not present there IS NO CHANCE of saving anything in case of malfunction.
Additionally if you are storing at someones elses storage lot, they may or may not be amused at the thought or notion that folks are leaving fuel burning things running unattended in their storage lots. I would recommend checking with the storage lot since if your RV for any reason causes damage to the facility or other property it may be you and your insurance picking up the bill (yes, someone won't be happy)...