if you are present at your PC at upgrade time you get a popup that you can select the delay between 10 minute and 4 hours. There's also nothing to stop you postponing for endless number of 4-hour intervals.
So, I get called away from the office with multiple documents open, and when I come back all of that is nuked because MS decided it was more important to reboot the box to plaster over yet another set of deficiencies - possibly borking the box as well, given the patchy patch quality? Now you know why I have updates set to 'notify', but I understand that's potentially no longer an option.
Some days I get the impression Microsoft's main mission is to hamper productivity as much as possible. On other days I'm certain.