The best way to make robbery obsolete is to encrypt the wallet (and device - optional) with a long passphrase (which you don't want to use as you're afraid) and the best way to prevent hardware failure is to have multiple backups (e.g. multiple USB keys).
I guess multisig is making the robbery obsolete, I can have one key stollen, but probably not two at the same time... Multiple backups increase the chances of robbery, if not encrypted. And yes, encryption make me scared of myself forgetting how to access to it
I don't think there's a singular best option. A simple example would be: [1]Open up a safe-deposit box (or make a hidden/'safe' compartment somewhere in your house) and store some USB sticks (or HDDs, whichever you prefer/have) containing encrypted wallets.
As said before, being digital nomad, I dont have fix house... I could get a safe somewhere I guess, but if I can avoid to pay for that, or ask banks to keep my btcs, better.
Multisig 2 out of 3: Wouldn't you have to place 'trust' in additional people (2 in this case)?
Yes I can have 2 trustable people. But... What's about one key on a ledger wallet (with me), one on copay for example, and one in my emails?
For being hacked, the hacker would need to have access and to my copay account and to my mails. If I'm losing my copay password, or my ledger, or access to my mail / mail compromised, I can still move my BTCs to a new wallet.
That way I can keep access to my BTCs from anywhere in the world, and I'm guessing they are safe from a hardware failure or robbery. Am I wrong?