What do you mean by "out of civilzation?"
Personally I would be hesitant to use a 20" bike in more remote areas like South America, or sub-Saharan Africa, or a mountain trail like the Great Divide. The roads are probably way too rough for 20" wheels, even with some suspension.
I'm not sure about the repair / supply situation, that depends on where you're going. For example I've heard that 26" wheels are good for use in lots of areas, because that's a more commonly used wheel size outside of the US and Europe.
At any rate, of the 3 the Llama is
probably your best bet, since you can build it up custom. Per Jur I'd avoid the Dahon.
Oddly enough the TSR8 seems, uh, reasonably priced for a Moulton machine.
You'd probably have to set it up for very low gearing though. I recommend you try a bike with an internal hub before buying one. Personally I find them a bit muddy and can feel the inefficiency; you may not mind it though, or will find it worth the maintenance trade-offs.