Thought experiment: What should be done if it becomes obvious that Quantum computers actually posed in imminent existential threat?

Let's say in the future, it becomes obvious that Quantum computers are getting close to the point where they will most likely be able to start cracking Bitcoin in a few years. (Some people say that now, but we're likely still far away)

If you did not reuse an address most P2PKH UTXO's are theoretically safe.

However, reused addresses, and legacy P2PK transactions are vulnerable to Quantum attack. Supposedly about 25% of Bitcoin is stored this way, and is vulnerable to Quantum attack. Such as a lot of Satoshi's coins. But many of these are "lost" coins.

Do you think there should be a hard fork change to the network protocol. For example: "If any of these quantum vulnerable coins do not move by X blockheight, they become invalid"?

or should Satoshi's coins be up for grabs to someone with a Quantum computer?