Batteries, generators and wi-fi, coupled with low-power operation modes for modern equipment, are going to be a quick answer to that strategy.
Cutting power will buy less than a week of opportunity, and piss off LOTS of other ordinarily unmotivated, apolitical people.
You don't need a week; if you don't have any serious opposition under control within a few hours, you've lost.
It might be a move interpreted in ways so politically costly, that you'd only trade a serious opponent in the short term, for an inertia of lasting public resentment that creates larger enemies down the road.
But, break some eggs and make an omelet. What do I know?
And I live in the oppositions main stronghold when it happened.
Couple hours of lack of information is all you need, and is easiest way to cut all with a single switch.
If your power cut out right now, how long till you have net? Your neighbors? Your block? Weeks.
Was rather brilliant to be honest.
How does the wifi work? How does the internet work? By electricity, and buildings that run using electricity. My router can run from a battery, but if my ISP isn't working, or if the fibre cabinet is out of power....