There are a number of small tweaks to existing algorithms that could be used to keep ahead of quantum computers. For example increasing the key length by 4x would require a larger number of qubits therefore slowing down the risk.

And the popular symmetric key crypto and hashing algs are known to be safe. So even without exotic new post-quantum crypto we can have a good amount of battle tested existing tools.

https://en.m.wikipedia.org/wiki/Post-quantum_cryptography