It's always a trade off between the risk of losing access yourself, and someone else gaining access. I've never found a solution that fully satisfies me.
Have you ever considered purchasing several hardware wallets (e.g. a Ledger S), initializing them with the same seed and storing them in different places (parents, a bank safe deposit box, ...)?
I would have no problem if the ledger should fall into the hands of someone else, I think it is impossible to guess the pin. Furthermore, to my knowledge there is technically no possibility to get the seed out of the ledger in that case. I am currently considering a similar scenario, whereby I currently like the storage of a backup ledger in a safe deposit box best.