Your question (the original poster's) sounds as if you are an RV'er looking to boondock on purpose?
Our situation is different, as we do spontaneous rockhounding mixed in with other RV activities. We boondock camp because we sometimes have to - out in the middle of nowhere - whether or not we want to at the time. What this means is we have to keep our rig in "boondock configuration" all the time ... just in case we find ourselves having or wanting to do it when we're out and about ... regardless of any trip plans when starting out.
We don't consider what is done, say, out in the desert around Quartzite as "boondock RV'ing", as there's too many others within eyesite to help fill-in for any lacks in self-sufficiency. The way we boondock we need to have our rig set up for lesser support situations, by taking along such esoteric things as:
1. Fairly complete tire servicing capability, including - of course a full size spare, an extended height hydraulic jack, a full power compressor, cans of flat fix spray, a professional tire puncture repair kit, and the ability to change an inner rear dual on our own on a soft surface if necessary.
2. Range extending cell phone access (... or some other remote access/rescue communication aid).
3. Decent on board AGM battery capacity, with three ways of recharging when there is no sun.
4. Both a built-in generator and a portable generator.
5. A comprehensive set of onboard tools - including such just-in-case things as an electronic remote viewing probe for inspecting broken things in behind walls, dash panels, firewalls, the engine block, etc..
6. A set of full size crutches for foot sprains.
7. Roof access via a permanent ladder because things can break or come loose up there.
8. A spare main engine serpentine belt.
9. Spare main engine and generator fluids.
10. Extra gasoline for the portable generator, that can also be used in an emergency for the main engine should the main tank ever run low.
11. Extra parts for the coach appliances and coach exterior maintenance.
12. A blood pressure monitor, a heating pad, wrist wraps for sprains, blood oxygen monitor, etc..
13. A full size shovel and a portable shovel.
14. Outside area, and personal, mosquito repellant.
15. A high volume 12 volt fan and an extension cord for it.
16. A built-in weather radio.
17. A couple of extended range walkie-talkies.
18. A portable electric heater that can be run off a generator as backup to the main propane furnace and the dash heater.
19. A full size beach umbrella for doing anything under a blazing sun.
20. A full length hardened steel tow chain.
21. A portable propane cooking burner and a portable propane BBQ as backups to the coach's galley cooktop.
22. Drinking water because we don't drink from the freshwater tank.
23. An outside shower for washing the dog every few days.
For what it's worth, here's a link to an interesting discussion on what "boondock camping" is:
http://www.irv2.com/forums/f93/rv-park-boondocking-off-the-grid-confusion-of-terms-274748.html
2005 E450 Itasca 24V Class C