If the national power grid were down for a month, I think a lot of people would die.
Right away, there would be rioting, looting, arson, and breakdown of law and safety in numerous cities.
Folks in bad shape in hospitals and some who need specialized treatment or medicine might die.
Within a couple weeks, there might be people in arid regions dying from lack of water, depending on how well organized are the groups that have generators and access to water.
There would be an economic crash that could last to well after restoration of power.