Good coverage of the major considerations. One (minor) comment: it's true that cryptocurrencies are dependent on an active network (and by extension, power). But if power is out for an extended period of time (like weeks or months), gold, except in the smallest units, may not be of much use for trade as well. Then things like silver (much smaller value = easier to use for essentials), and even barter goods (cigarettes, toilet paper, rum, etc) become even more useful. An extreme consideration, granted, and hopefully not the likely scenario!