This seems like a use case for an offline password manager (which will no doubt still run on the same device, and therefore offer limited benefit), or doing som

This seems like a use case for an offline password manager (which will no doubt still run on the same device, and therefore offer limited benefit), or doing something like gpg encrypting the information to your own gpg key (and storing that key offline or on a yubikey, and not putting the gpg private key on the computer with access to your password manager).