What is your experience with storing offline files and where do you recommend storing the files?
This sounds like an interesting discussion topic Anyone have any personal advice/experience to share?
By offline do you mean something like a cloud storage service, not your company's internal network? If that's the case, Box.com and dropbox.com have worked for me. Domo uses box.com pretty heavily internally as well. OneDrive is an option also, which my company Merit uses. For simple storage and retrieval, any of these would work fine.
To integrate with Domo, unless things have changed recently, I'd recommend box.com over dropbox. I've found the Box connector to work pretty well.