Yep, I can go about 500 miles with a full tank on my Expedition. One tank away from large cities would put you somewere in Canada or Alaska. You do know in a total emergency situation, the Interstates will be isolated for military traffic only. Might have to use US, state, and county highways. I know of someone who left New Orleans when the flooding started. He grabbed all his guns, his family, family pictures, as much food and clothes they could load in their SUV's. He had already filled up when he saw the Hurricane was coming. He knew not to leave via the interstate, but followed a US highway to Vicksburg, MS, then went to Birmingham where relatives were. At his home in NO, he had two generators, extra fuel, food and water stockpiled in case of long term power outage. When the levee broke, he knew it was time to leave. He left a day or so before the panic.
I guess the best places are in the country within an hour drive of a big city. Ability to farm, raise animals, and be self sufficient "off the grid" in an extreme emergency. Gasoline might be hard to get once it got that bad, so some of the perps in big cities might not make it out. If martial law is declared, cities will be where the guard or military units will go to keep the peace, and give handouts of food and water to the non-preppers.
Worse case senario is like in the book "Patriots, Surviving the coming colapse" by Rawls. No national guard, no police, no military, because no one can get paid, so they walk off to take care of their families. Then you will really need to be prepared in a very remote place.
Problems:
1) Northern rockies and plains states "might" get covered if Yellowstone erupts. (It has risen 3" a year the last 3 years, more than any in recorded history). Just something to think about. Might not be in our lifetime.
2) Southwestern is much dryer, so water can be a problem, and there is the problem of illegals flooding across the border if our nation colapses.
3) Appalachin mountians and foothills. Lots of big cities within a gas tank away. Lots of cabins for tourists. They might become flooded with people.
4) Southern coastal areas are prone to hurricanes.
5) Western coastal areas might be prone to a tsunami, although these are rare in America, and most people in the "left coast" are liberals, but the California perps might head north to Oregon.
6) Alaska might be ok, but it is remote and cold.
7) The plains states have sparse population, but tornados are a problem, unless you build underground.
Ozarks might be ok, but there again, people coming out of St. Louis and Little Rock, might head for the hills.
So where do you locate. I say within and hours drive from your job as remotely rural as can be, away from interstate and US highways, and maybe even state highways. Know your neighbors, build or prepare defendable location in case a gang of perps find your location. Might be stupid, but that is my opinion. Keep it low key. You can prep with only $20 a week for supplies, food, ammo.