I am not sure. I know China won’t join the party soon because they think they are invincible since they own all those rare earth mineral mines in Africa and their mainland. They probably favor gold over btc too.
China isn’t easily influenced by current market trends. More likely they would even want to make their own version of bitcoin. They are so determined to keep their control over their citizens so pushing for a decentralized currency may not be on their plan any time soon.
Other than that El Salvador is a good pick for obvious reasons.
According to
this, Russia, Brazil and Poland may all also thinking about buying bitcoin but highlights that they might do it in secret.