I would think Canada would do a bit better than the US, since hydroelectric supplies almost 60% of Canada, and hydroelectric could probably keep going without operators for at least a few days. The US is more than 50% supplied by coal, and coal plants need a new supply of crushed coal every few hours. But either way, the rolling blackouts are going to be starting within 24 hours.
The moral of the story is: keep up with the routine maintenance on the solar panel on your survival bunker.