The author appears to be an individual who digitally documents events as mundane as eating. I don't think going days without an internet connection is a big risk for him.

Personally I just keep an encrypted flash drive with all my passwords and documents in a safe. My whole family knows the password but they don't know the combination. If I go missing they can cut the hinges off in minutes with my angle grinder. They can't access it without me finding out and hypothetical burglars wouldn't be able to decrypt it. Simple and doesn't rely on any external services.