Northeast/Mid Atlantic
South
Great Lakes
Texas and Great Plains
Pacific
Mountain
The way that will change, if ever, will be through state party committee and through RNC. I think it will change soon with the aggressive primary moves by everyone these days.
Somebody here proposed having the primaries in order of the states which had the highest Republican turnout in the last general election. I like it for several reasons, one of which is that it encourages more Republicans to turn out to vote in “safe states”. Also the states with more Republicans reduce the chances that Democrats voting across party lines will affect the outcome.