I agree that it's very hard to stitch in the ditch on a queen-size quilt. BUT it IS possible. Try using spray adhesive. It works much better than pins when you're using a home machine to quilt. And rolling the quilt makes it harder to move the quilt than just smushing it. The roll acts like a stiff log, and it goes where IT wants to go rather than where you want it to go.
Hang it there!