i used to baste, then roll from each edge to the center, then, starting in the center i worked from the center to the right, unrolling as i went. when i got to the end (edge), i removed it. i rolled it back up to the center, put it back under the machine in reverse, starting quilting to the right again until i finished at the other end (edge).
i supported the quilt on extra folding tables.
by using this method, you never have too much fabric under the arm of your machine at one time. worked for me.