I am currently making a 118" by 65" hex tarp for my Blackbird. The minimum distance across the center of the catenery cuts on the sides is 56.5".
I scored the deep forest green 1.1 silnylon (actual 1.36 oz/sy after coating) from Quest Fabrics because it is 67" wide. I have no ridgeline; it's a single piece with 90* angle (45* each side) at the ends of the ridgeline. A total of 4 SY of fabric after the cat cuts weighing 5.5 ounces!