If you do not reuse address, you public key will not be exposed and you are safe. That alone is enough.
Anyways, one way I believe a way to keep your BTC safe, and I was expecting it to be the first on your list is the use of Hardware or Cold storage wallets, because these wallets operate strictly offline, making it difficult or should I say impossible for hackers to infiltrate, even with the help of a quantum computer.
If bitcoin private key is no more safe with quantum computing and the public key of the private key is exposed, regardless of the wallet that you are using, the private key can be known as long as the public key is known. OP is very correct and added cold wallet is off-topic tonehaybhenis discussing.