[mariojv]

Would they need to do it all at once like this? How have other countries that have officially dollarized handled the transition, if there are any major ones?

It looks like the list of countries besides US that exclusively use USD is small, none with a population over 100k, although I know several economies have de facto dollarized: https://en.wikipedia.org/wiki/Currency_substitution#Countrie...

Maybe that Wikipedia list is out of date. I'd thought Ecuador was running on dollars.

[slooonz]

The entirety of the European Union changed their national currencies to a new one, from scratch (no prior partial euroization), essentially overnight, in 2002. It’s definitely doable, if properly planned.