of you can use the old school https://bitcoincore.org/en/download/ just save your private keys and store your coins for a long period of time. there were rumors that if you make a transaction using the same address you use to conduct a transaction, it would mean your public key will b exposed and that a quantum computer might just be a threat and can also expose your private key. not sure if it's possible but store your coins and not use the wallet afterward. not even once.