Since I am in construction mode:
the West might contain California, Hawaii, Oregon, Washington, Arizona, Colorado, Nevada and New Mexico (population 71m);
the Northwest might contain Maine, New Hampshire, Vermont, Massachusetts, Connecticut, Rhode Island, Pennsylvania, New York and New Jersey, as well as Puerto Rico, Delaware, Maryland and DC (population 67m);
Florida would be its own entity (population 21m);
the South would include the states of the old Deep South across to Texas (population 104m), unless Texas went on its own (population 29m) or decided to hook up with Florida and the states along the coast in between (population 63m), leaving the South with 63m as well;
and the Mid-West would contain everyone else (population 66m), if the Mormons don't want to turn Utah into its own zany country.
Five countries, each of which would be a substantial nation in its own right, living the way it wishes to.