Yup, you can take 6-9" easy. I took six inches off one of mine.

Moving the buckles closer together is pretty easy. The nail biter was cutting a new hole through the pleating for the strap on the inner apron to pass through.

I ran blanket stitch, sometimes called whip stitch around my new strap hole to keep it from fraying. The whole process took about two hours, but I do have some hand sewing experience.