A few academics have looked at the ways the US is really a collection of regions that might evolve into their own separate countries.
The Nine Nations of North America breaks the US up into these regions:
There are variations on this theme; here, by Colin Woodard, are eleven nations, with some finer detail at the county level:
Now, this is all well and good, but some of these maps and re-imaginings were done years ago, and with a vision that this would be an administrative shuffle, not something brought up by the stresses of a changing environment and energy. They do point out that our current administrative divisions are arbitrary at best, and practically no states have been untouched by these imaginings.