I would create a wallet and print it in a qr code, and I would keep it safe in a paper wallet. To me this is the best way to keep it secure: making it a physical piece of paper and maybe you can tell somebody you really trust where are you hiding it (just in case something happens to you… je).
Nevertheless, your method is strong enough, I’m just the kind of person that prefers to conserve my money behind the pillow, as an old man.