Before the Anniversary Update the system was rock solid (even with 3301 BIOS). Power management worked fine and the system didn't freeze.
The problem started only during update installation (I've managed to install the update after 5 attempts since the same BSOD caused failed updates and rollbacks to the previous build).
changed "Minimum processor state" from 5% to 40% in the Balanced power scheme and it seems to help (at least no more freezes for an hour).
WINDOW +I -->SYSTEM-->POWER & SLEEP -->Additional Power Settings --->Change when the computer is sleeps -->Change advance power settings
--->Process power management-->Minimum processor state