While sufficient to travel to a destination of reasonable distance - stretched to weeks or even months a 72 hr kit is going to run dry very fast unless it includes the longer term makings of water, food, shelter etc.
I've spent quite some time mulling over responses to your post.
Suppose my concerns break down two ways:
1. Well ... yeah.
It's a "bug out bag", not a "long term sustinence" bag.
It's for when you have to drop everything and GET OUT NOW, giving you about 3 days to either get to an equipped long-term survival location or otherwise figure out how to deal with TEOTWAWKI.
You can get along just fine for about 3 days with a proper BOB, which is about how long a real SHTF situation will take to either subside or transition to long-term survival.
It's a "get you through the surprise when you've got nothin' else" bag.
2a. Certainly make use of the fact that you have a vehicle. Prep it appropriately.
You can use a vehicle to stock survival stuff you won't be bugging out with but might want so long as you can drive: ax, cases of food, case of ammo, big tent, warm blankets, long-term feminine needs (desperately trying to stay on topic), etc.
2b. What bothers me: If your conveyance is powerd by oil derivatives, it will likely be useless after 1 day when SHTF.
If you really do need that extra long-term gear in the vehicle, the situation is probably such that there won't be enough gasoline available to keep it running. Extra gas cans, if filled in time, will help but not indefinitely; make sure they can be transported outside the cabin (trunk doesn't count), lest you die early from the fumes.
I became keenly aware of this right after Hurricane Katrina hit: being in the Atlanta region, we suffered no effects from the storm ... except gas shortages. Even with full gas tanks, I became keenly aware that if I traveled anywhere
at all, the vehicle rapidly headed toward useless. If used at all when gas stations have been emptied by mass panic, a car becomes a one-way ticket: you'd better know where you're going and be able to get there, because once that tank is empty you're stuck. If the tank is less than half full, don't even bother starting - just hunker down.
99% of the time, your "conveyance" will be a car/truck. Yes, it can be stocked with long-term gear ... but if you're going to do that, you might be better off making sure you can get to a much-better-stocked home, camp, or cache. Aside from some notable tools and a sack of rice, you're realistically not going to load up the car with serious long-term sustinance gear; the storage is too small, especially given daily usage.
1% of the time, you may have other vehicles. A boat can certainly hold more gear, and may serve to get you away from mobs long enough to restore order or sift the population down; boats are rarely prepped enough for indefinite occupancy, and require periodic serious resupply. Airplanes won't give much more storage than the trunk of a car, but will get you way the heck out of a SHTF zone; unfortunately, as per 9/11, expect shutdown of airspace (enforced by shootdown) if SHTF is induced deliberately.
0% of the time you'll have pack animals and a reason to use them. They're on a farm - if SHTF, a farm is the best place to be. Don't go anywhere.
Yes, there's more to survival planning that a bug-out-bag. The BOB keeps you going on foot 72 hours. Stocking supplies in a vehicle is best focused on getting you to a "bug-in" location, already prepared for the long haul. Yes, keep some long-term gear in the car - but be aware of where that car can go.
BTW: I increasingly doubt the usefulness of stocking stuff for barter. Once you get to that point, those who need what you have probably won't have what you need. The prepared won't need to; the unprepared won't be able to. Keeping a few $5 "dollar store" micro-BOBs to give away might be good though: for $5 you can get a sack, bag of rice, cooking pot, matches, and knife - useful for taking pity and getting the surprised out of your supplies.
