You don’t. It’s not networked. It doesn’t need updates.
replyIn fact, updates are only a risk. You physically remove anything that can allow updates to happen + anything that allows wireless networking.
Then your scheme falls apart as soon as a backwards incompatible update is adopted by the blockchain.
replyHow do you actually use funds like this? I mean, I know this is set aside for later. But if you had an emergency, how fast could you actually spend it?
replyTrivially. You can simply read the keys on the offline machine with your eyeballs and set up a software or hardware wallet elsewhere to access the account.
replyWhat is the offline machine even doing then? Seems like you could replace it with a sheet of paper.
replyUSB flash or QR code to transfer data
replyI agree my approach is not great, I dont own a lot