I think it is fine. However, I took a similar problem to a very accomplished quilter friend and this was her advice. Pin a thin blanket to the floor very tightly. Pin your quilt as tightly as you can over that. Make sure it is square. And then just iron it with steam. Some of the extra fabric will disappear if you have prewashed. I have done this successfully. Let your quilt stay pinned for a day. Then if you need to add more quilting, etc., it will be at least easier to do. Hope this helps.