I love to play with number so lets see if my work is the same as yours...first, the super fast jelly roll quilt I'm thinking about is the one where you stitch the strips together end to end, fold in half and stitch those together and repeat...is that the one you're talking about?
If so, I agree that it will be a very looooooooog strip - that being said, a queen size quilt with a ten inch drop measures about 80 by 90 and translated into square inches that comes to 7200 square inches finished. If you translate the jelly roll strips into finished dimensions, I calculate each strip will finish out at 2 inches by 41 inches (of course the 41 could be 42 or 43, depending on the fabric width). Multiplying that finished dimension, 40 strips that finish to 2 X 41 comes out to 3,280 square inches. That means you'd need three jellyrolls to complete the queen, and you'd actually have enough there to make a quilt about 96 by 98...which is a queen with an 18 inch drip. you can also reduce the amount of the drop and make it longer to include a tuck over the pillows.