I'm thinking your best bet is a full-size diesel on a truck frame.
If you don't have kids, an extended cab would provide enough concealed storage to get you home and then some. If you do have kids, then you'll probably need a quad cab and maybe a sturdy, locking toolbox. A suburban would be even better.
I just can't see myself driving any full-size vehicle in SHTF, unless I was in dire straits and needing to move the whole family somewhere fast. I figure dirtbikes would be the primary form of transportation - far more fuel efficient, mobile, easier to maintain, and harder to catch if you need to GTFO.
Hell, even if I were in a position where I had to move people in a full-size vehicle, I'd want a couple outriders on bikes to scout and provide support if/when we broke down or were threatened.