That came out lovely. Consider quilting it in thirds.
Lay out back, batting, top. Carefully roll back top on one end and cut out 1/3 of the batting. Repeat with the other end. Roll back top and spray base or pin all three layers. Quilt that middle section to about 1 inch from the end of the batting. Add back one second of batting on the end and spray baste or pin that section of batting and quilt that end. Repeat with other end. Easy and so much less bulk you have to work with at one time.