The trouble isn’t that you can’t do all that. It’s how many other people have that same idea. Rural areas will be overrun by people who think getting out of the cities is the best idea – not that they’re wrong – but it will run supplies low outside cities too, and home gardens and the local deer population can only take so much pressure. That’s not even to mention the road traffic. If cities can’t handle rush hour, 2 lanes will certainly be gridlocked as everyone looks for the next road not taken. The locals would not take kindly to such an influx either.
The best strategy in my mind would be to stockpile food and other necessities wherever you are now and prepare for a long wait, hoping power gets restored. It would be horrible and dangerous no matter where.
3 months is when my insulin runs out. I doubt I’d make it that long in the USA.