I know the higher amount of travel is a factor, but I don't think it would be that much more travel.
For perspective here's current state and possible rotation combination for the New Castle SS. I tried to match up with the next most optimal regional distance to shorten miles.
New Castle's Regionals Current state (odd years)
North Montgomery= Crawfordsville, Frankfort
Pendleton Heights = Elwood, Lawrence Central
Perry Meridian = Southport, Shelbyville
Richmond = Tri, South Dearborn
NC's Proposed regionals in (even years)
North Montgomery- Crawfordsville, Lawrence Central
Pendleton Heights- Elwood, Frankfort
Perry Meridian- Southport, South Dearborn
Richmond- Tri, Shelbyville
Here's a rough estimate of each traveling sectionals increased Mileage ( Delta of miles from former regional to new regional
Frankfort Distance to North Montgomery= 33 Miles Frankfort to Pendleton Heights = 50 Miles Delta =17 miles increase
Lawrence Central to Pendleton Heights = 24 Miles Lawrence Central to North Montgomery = 57 miles= Delta = 33 miles increase
Shelbyville to Perry Meridian HS = 30 Miles Shelbyville to Richmond HS = 62 Miles Delta= 32 miles increase
South Dearborn to Richmond = 63 Miles South Dearborn to Shelbyville HS= 66 Miles Delta = 3 Miles increase
Now each high school would have there own travel distance increase or maybe decrease based on the new regional, for a quick SWAG, I used the distance from sectional to regional to give us a general idea on the travel increase.
Generally, teams in the worst case scenario will be traveling a half hour to 45 minutes more.