I am actually a recent convert to the ways of the Trailer and RV...
However I've been backpacking and 4x4 traveling the back roads long time.
I just thought I would add, that I always have a certain amount of "survival" gear in my truck, and leave it there because I am often up in the mountains somewhere probably pushing the limits of the vehicle, my gas supply or just my luck in general.
There's always a pocket knife and multi-tool floating around in the cab. there's a mini first-aid kit under the seat.
Whenever I hit the dirt roads I throw an old army surplus backpack I have in there that has zip locks with waterproof matches, panchos, emergency blankets, compass, knife, dehydrated food, T.P., random first aid items, and water bottles that have built-in filtration.
it's an extra bag, I never unpack, just for throwing in the back when you "hit the dirt".
If it's really wet/rain/snow area, I'll even leave some firewood in the back (it has canopy).
As a side note, ALL of our backpacks, and day-packs, (adults and kids) ALWAYS have a small kit of survival essentials;
water proof matches, pancho, em. blanket, first aid, water filter bottle, and a mini fishing kit. All of that fits in a surprisingly small space and weight. (<3lbs ???)
So even if we just grab a day-pack for a hike, we know it always has that in there. just in case.