My condolences, and thanks for sharing your pain to warn those of us who also live far enough away from older family members that this could be an issue.

[Edited to add] This also made me think about a late uncle's various Apple things that my rather tech illiterate elderly aunt still uses - under his Apple ID. I really need to put them under a new ID tied to an email address I control so that she doesn’t get locked out without recourse - a project for the next time we can visit her.