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? I

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#Countries_and_regions_using_the_United_States_dollar_exclusively https://en.wikipedia.org/wiki/Currency_substitution#Countrie... Maybe that Wikipedia list is out of date. I'd thought Ecuador was running on dollars.