When I want to find out way too much information about coffee, I turn to coffeegeek.com
Conclusion he reached:
1) Coffee brand doesn't much matter much. Use cheap coffee. Cold-brewing does not produce all of the flavor compounds as hot-brewing.
2) Extraction time anywhere between 12 and 24 hours -- doesn't matter much.
3) Use 167 grams of water to 25 grams of coffee. This produces (120.4+170) 290.4 grams (which I'm assuming is 290.4 cubic centimeters) of finished coffee, which is 1 big mug of coffee. Obviously, this can be scaled up.
As for grinders -- for an espresso machine, uniformity of grind is crucial, because the extraction time and pressure can vary, causing straight-up bad results. For a french press, uneven grind means that grit finds its way through the filter. For a drip or pour-over, there's almost no grit ever, so the grind might affect the flavor, and how much depends on how critically you taste.
So I'll add my own conclusion:
4) For a cold-extraction, the brew time is so long, uniformity of grind probably doesn't matter a bit. Smashing the beans with a hammer is probably adequate.
Obviously, the #1 concern of Cory is producing a decent cup with absolute minimum investment of time and suitcase space.
1) Weigh a hotel-provided coffee brewing "beans in a paper sachet". (You'll only have to do this once.)
2) Multiply by 20/3, and add that many grams/cc of water, and the bag, to a pitcher. Question: Does this fit in the coffee-brewing carafe? I suspect it might!
3) Wait 12+ hours
4) Squeeze out the sachet into the pitcher.
5) Add enough water to double the contents of the carafe.
This would produce cold-brewed coffee that requires ZERO packing.