If we take every dollar in existence and make the existing quantity of BTC equal that amount of value, what will a coin cost in the (now-defunct) dollar?
Just wondering what will happen if a large economy switch to Bitcoin
There's no such way, Bitcoin is decentralized and the dollar is centralized, I don't think that the well-developed country will do such a thing, they even have heavy regulations. Bitcoin needs also fiat to have a real value and I don't think it can overtake with Bitcoin besides no one government replace their fiat.