I just made a jelly roll race using two jelly rolls. It's 58 x 84, so twin size, no borders.
I 'raced' the quilt length-wise, and made it 84" long because lots of my family members are tall!
You could 'race' the quilt across the bed or down the length of the bed in sections with sashing between each section and on the borders. That ought to get you the full size quilt you're thinking of.
Good luck!