Hypothetically if one wants to never open the ledger again and has been avoiding updates for over a year or more. Would a secure temporary solution be to open the seed on a Cold Card and add an encrypted password?
Discussion
Adding a passphrase to a seed generates an entirely new wallet, so either way you would need to send your funds to the new wallet.
You are better off leaving the existing seed on Ledger (since it may be compromised), generating a new seed on a new wallet, and then transferring funds to the new wallet.