If you use the following measurements to modify the design, you'd get the same exact proportions, but be able to use the packs/rolls/WOF you have.
Larger squares = FINISHED 8-3/4 (cut 9-1/4")
Smaller squares = FINISHED 1-3/4 (cut 2-1/4")
note: don't have the pattern, never made it, just looking at the picture.