The overall goal is be able to backup your information safely and restore it completely with minimal amount of information that you can remember without writing it down. This will significantly increase your chances of restoring your information in case of theft, robbery, accidents or catastrophies.
Information should be backed-up regularly to several off-site storage systems using encrypted borg repositories. Make sure that you can restore all your information using the information you already know or is readily available to you. For example you might have separate repository that contains your password manager's database, using a strong passphrase that you can remember, which can be used to further retreive information from other repositories.
In event that you completely lose all your information (including local backups), you need to restore it from off-site, which you cannot do directly since the keys you need to access it are lost too.
To mitigate the use of passphrase authentication to remote backups, you issue special security-hardened emergency keys to individuals that you trust. Note that these keys could also be placed at secure off-site locations that you have physical access to. You may also choose to carry one with you at all times on an encrypted device of your choosing.
The passphrase should be known only to you, and be somthing that you can remember. This ensures that only you can access your backups, without any additional information that you don't already know.