Right, I just have to show my zombie apocalypse vehicle then.
We could live in that for 3 months without trying, probably 6 if we knew in advance to get more stores in and were careful with water...but that then?
Assuming a
hostile environment (IE total breakdown with roaming gangs) the only way to stay out of trouble is to never be seen by anyone and I don't care what vehicle you have it's vulnerable for a 1000 reasons, not the least of which is people can see it, and if they can see it they will want what it has, and if they want what it has they will probably get it.
By all means have a bug-out vehicle, but it's only purpose is to get you out into the wilderness, you then ditch it and start walking. From now on you live off the land, something of course almost none of us can do so we're screwed. By all means have a firearm but it's for self-defence and as a last resort, it is not for hunting because the sound will alert others of your presence and once they know there is someone to look for they might start looking, and once they start looking they will find you.
So it's a bow, crossbow, snares, digging for tubas etc. It's all been done before, just not by people like us so as I say, we're probably screwed anyway.
If the breakdown is not hostile (IE the "system" just turns to ******** but there is still law and order, kind of like what it is already

) then I would agree with Montereyman, a farm is probably the best, drop the hi-tech, get a horse, learn how to do blacksmithing etc etc.
In this scenario a truck like ours would be good, we have 6 months to learn how to live off the land, probably not enough but at least we'd have a chance.
A third scenario is the
natural-disaster one like Katrina, as mentioned we are fully self-sufficient for months, unless we were at ground zero I doubt we would have noticed unless we turned on the TV, at present we are not fussed about storing much food, but even then we only go into a town about once a month.
And finally, the best thing you can do is move somewhere that's warm, in northern Oz all you need is a tarp to keep off the rain in summer and a pair of shorts (actually they are optional), there are no life-threatening climate issues so half the job of survival is done. I reckon in six months you could also learn to live off the land, in the tropics it's all there for the taking, you just have to know where to look and what's not good for you. (Note to self, buy a bush tucker book)