My Husband Just Died and I Want to Unlock His Phone.

If you are in the Apple ecosystem, consider establishing legacy contacts. Apple will require a death certificate be provided before enabling access.

https://support.apple.com/en-us/102631

Keep every pin and passcode in an app with the encrypted safe or copy on a thumb drive or even file share. It's encrypted. Even your phone pin. The app just needs the one (Very long) key.

Give it to a trusted person with the key, or just the key if shared.

Or variations of the above.

Fire danger? Store your key docs in the same storage. Encryption not needed. I do keep originals in the evac kit.