It's a nice thought, but economically speaking, even if massively adopted, BTC couldn't save a country from bankruptcy. A currency that they cannot control wouldn't become the primary currency of a failing economy
Exactly,a country's falling economy has certain conditions,say political instability or due to ongoing conflicts.Adoption of decentralized currency wouldn't do any good
Adopting a decentralized currency could calm some of the political instability. If the government cannot print money at will (and spend as much money via printing additional money) then there will be less reasons for corrupt politicians to try to come into political power in the first place.