After a long drive to the inlaws today, I thought about this some more, I don't think you would have to add another week to the season with the format I suggested, you would do the following:
The last weekend in January is currently used for the Region Duals, you could do the Region Dual matches during the week and use that weekend for the Regional tournaments, the 1st weekend in February would be the State Duals, the 2nd weekend in February would be the Semi State or Substate, and the third weekend could still be the State tournament.
In Indiana, not sure if they still do it the same way but they used to when I coached have the 1st rnd of the individual with the winning team from each of the Sectionals be declared the Sectional Dual champion, the Sectional Dual champions would meet during the following week to compete for the Regional dual title, the Region Individual would take place on Saturday, then the Semi State Dual tournaments would take place during the week, then the Semistate would take place on the following weekend, then next weekend would be the State Individual, and the weekend after that the Dual state would occur.
I thought about the rotating combination of Regions, but I am not sure that the Board would go for that due to travel expenses.