Stellar's quantum plan means you never have to move your coins
Bitcoin's problem is that exposed coins have to migrate to new addresses, and dormant ones never will.
@StellarOrg is going the other way.
Because an account is an address and signers are just mutable state, you'll be able to attach a quantum-safe signer next to your existing one. Same address, same history.
Soroban gets it this year. Classic accounts in 2027. $XLM