It's even more unlikely because you then have to find a buyer that's willing to pay market price for the gold wherever you end up at. You'll be reduced to selling it for whatever people are willing to pay.
In the past it's been mainly useful if you can flee from a region in turmoil to one with more stable conditions. For example, my grandfather fled Turkey for Greece in the late 1910s (http://en.wikipedia.org/wiki/Greek_genocide), taking some gold with him that he was then able to sell in Greece, using the money to help resettle.
Many wealthy people in vietnam were reduced to nothing when the currency became useless. The few smart people who had gold were able to move their wealth out. The entire world is going to go to shambles at once, that is a very low probability event compared to a region. Even during WW2 there were regions that were relatively untouched by the world war.
