That's fascinating.
It's possible that she's going into hiding to prepare for her upcoming debates. You'll remember that she did that for many weeks before she was willing to face Bernie Sanders. It's also possible that she's so medically unfit that she simply cannot campaign. I'd think that this latter is the more likely. Donald Trump is no Bernie Sanders when it comes to knowledge of the issues. He's new to politics, after all. And we've all seen how Hillary has deteriorated over the last month.
Either way, it's remarkable that this close to the election Hilllary would be taking significant amounts of time "off." Obviously, she's got serious issues.