In your scenario, Texas will attract most if not all of the now known as “Red” States.
I am all for letting the stupid liberals keep their Blues, Left Coast and Nuevo England. It won’t take long before they come begging for “us” to rescue “them” from all the Come-Yets.
I do not know how many regions there will be. It will likely be more than two, but who knows. Geographically, how would California unite with New York when you would have another nation or two or three in between?