. Keep some of the wallets entirely hidden, for example by using a passphrase on top a seed phrase which has some coins stored in it, or by creating a hidden encryption volume, and putting one wallet in the non-hidden volume and a different wallet in the hidden volume.
The key here is not to overdo it otherwise one may end up like that guy who encrypted his IronKey and lost password that unlocks that encryption. In the result 7,002
BTC seems to be lost, I said "seems" because he only has two attempts left to access his fund.
referenceI am not familiar with IronKey, but I would think it would be possible to copy the (encrypted) contents of the hard drive an arbitrary number of times to allow for additional password guesses.