That may be. Still, much the same design (if a tad shorter) could still be used here to add cargo space within those limitations.
Owner operators are already making the most of what they have. One big trick is to widen the trailer by 2 to 4 inches at the roof line where it is rarely measured by dot. Another way is building belly boxes. The problem with using a cab like that is forklift access and load shift in a wreck. You would be amazed ay how efficient truck drivers can be.