This is an excellent point, Thom. I've found myself stuck noise pointed up hill, no traction, rear-end butted up against a mud bank on several occasions. Having all my gear locked up like that would have brought teh suck.
I have not found myself in that situation ever. Yet. Actually, I don't think I've ever seen a configuration of land where that was a possibility. But that's just the peculiarity of this area I guess. You can only ever dig so much mud before you hit rock bottom. Canadian Shield typically has 1-3 feet of mud, then rock.
However, it does still need to be planned for. In the past, I have forseen when a particular piece of trail is going to bring teh suck, and I put my recovery gear up front in the passenger footwell. Or even attached the tow strap and coiled it on the hood or spare tire.
But still, I'd be leary of having my gear locked away in the back any time. This is why maybe the false floor is the solution. Worst case, if you made it with no backing against the rear seat, you could flip the rear seat forward and get your gear from the front of the storage binnacle.
I've also thought about some kind of container on the swing away somewhere (I love the steel barrels that put it in the spare wheel). Or possibly a box bolted to the floor of the rear seat area.
That might actually be the best place for me. It would still leave the sides open for the kids feet. It would be sort of a continuation of the center console up front. Of course, this would then preclude ever flipping the rear seat forward. I'm not sure how much of an issue that would be in the future considering we have a minivan.
Ideally, I'd love to cut the middle out of the rear seat and make a larger box in that space, but there's no nice way to do that.