Joan,
Yes, it will work. Karen Kay Buckley, who teaches in this area, quilts her bigger quilts in three sections. I believe she said she cuts the batting in three sections, rolls the right third of the top, quilts the center section. She stitches the batting together, gets everything flat and then stitches the right third. She adds the left section last, turns the quilt about and then quilts the remaining third. -- AND when you see her work, you cannot detect that it was not all done at one time.
I hope this is clear?? Or in other words, the top and backing stay in one piece, she just removes 2/3s of her batting from the left and right side keeping the center 1/3 intact, quilts the center and splices each outer 1/3 back before completing the quilting.
Good luck and be sure to let us know how you make out. Suz