Just to point out July 14th.
On that day without warning W10 Update started downloading KB3172985 Cumulative update to v1511 at what seemed like a megabyte a minute but which had grown in 3 hrs to over 2Gb, during which time access to most sites became virtually impossible.
With a 15Gb month usage limit and no real indication of how much was still to come (the counter in W10 Update sat on 61% for over an hour) I turned it off (set to Deferr then set [2 notify to download notify to install] through gpedit.msc/AdministrativeTemplates/AllSettings/ConfigureAutomaticUpdates).
Since then, of course, W10 update is off and will just have to wait till the end of the month and I see what usage I have spare.
But there's another massive update due in August.