it'll survive no matter what, but how well the price fares is a matter of time. if a global financial crisis began tomorrow, i think bitcoin would fall on really hard times. if the crisis begins 20 years from now (after bitcoin has grown exponentially network-wise and matured as an asset class), i think it will hold its value much better. maybe we'll find some middle ground between these two scenarios.
I also believe it will very well survive if a crisis creeps up in 20years time as you have made the analogy. However, my issue about such crisis (if something like warfare), will disturb network facilities but if for just economic crisis, bitcoin will survive because it would have been around the breadth and width of the world.
