A big EMP event (either nuclear or a solar CME) would disable the grid for months or more likely years. Congress funded a study in the mid 2000's that is very educational. The estimates for American loss of life ranges from 50 to 90% after one year. If that seems too high ask yourself how many people would be ok after a week of no electricity which for most would also mean no water, heat, or food. People would be dying in droves within a week from drinking polluted water.
An EMP is a truly scary scenario and given the failure of Congress and the utilities to take preventive actions it's been left to the individual to prepare as best he can.
Polluted water will take more than a week to kill you. But the level of stomach discomfort WILL make you wish it had.
You failed to mention the other issue that will take a bit more than a week to be a significant reason that people are killed. That being other people. When faced with a real survival situation, people will revert back to 'any means necessary to survive. It they THINK you have any supplies or food they will be willing to kill you for it. And your radio will do you no good at this point. No one to call for help. The police will NOT be coming.
Sitting and blaming congress and the power companies for NOT doing something to mitigate the destruction of the grid due to am EMP is frankly silly. There really isn't a good answer to that problem. You are talking about an amount of energy that will be similar to a direct lightning strike or possibly worse. The electrical grid is well protected from a lightning strike due to grounding and creating paths to ground for lightning to follow instead of it hitting the live conductors. This works well for lightning but will do NOTHING for an EMP as that is energy induced on anything conductive including the grounds and live conductors. The longer the conductor the more voltage that's inducted. The failure will be the breakdown of the insulation in the transformers feeding the live lines and arc over from the secondary of the transformers. Again, not much that can be done to prevent this. The transformers will be destroyed and once that happens, it will take months or years to repair.
Transformers are wound by machines, if you have no power, you are hand winding them. That's a simple enough process for a pole pig that is 12 inches in diameter. When you get into substation transformers that are the size of a large truck or bigger, things change. And this is where the time will be required. My guess is that many of them in this situation will be rewound on site because moving that stuff is not a simple task.
And frankly, it's not something the average lineman is going to know how to do.
And once stuff is STARTING to return to normal, the amount of rationing will be huge. Fuel and food being the obvious things being rationed as the need for fuel for trucks and equipment to rework the grid will be top priority.