How is this in any way locally sustainable. If you want to shelter people then the people need to be able to build and sustain that level of technology.
Possibly, you're not dead so it worked. The better solution would have been ORS, and water. In the military and other physically demanding activities with a culture of water drinking, a concern can be hyponatremia.
Fermor is part of a whole cast of adventurers, like Richard Halliburton who lived life to the hilt. They lived in a certain time in place, where technology, access, risk, and the unknown nature of the world made classical adventure possible. Really good stuff.
I always figured one of the drivers for this was that the NSA basically mandated that this feature to be built into any printers it would buy (or let be bought). The power of the federal/DOD purse is a thing.