Yes I ever thinking like what you are. Now I get the solution . Why you not just make a secret code or something like that to preparing if you can't tell to anyone that you have a lot of bitcoin? I think you can tell it to your wife or your son about your secret. For an example my wife didn't know about bitcoin, but She knows that I have a bitcoin. So I tell her, if something bad happen to me, just keep my phone or my PC and learn how to exchange bitcoin to FIAT. Offcourse I protect it with a password which only me and my wife know it.