Would you be able to work if Internet was down for any kind of reason? To make it possible to at least survive you should consider using tools that keep offline copies (on your computer) of the data.
For example
- Mail if you use gmail, you can keep a copy of all email (and reply, write, etc…) by using a mail client like Thunderbird or Apple Mail or Microsoft Outlook
- Documents: Google Docs offline
- Home finance: GNU Cash