I would add more pieced borders until your center is at least as wide as a CA King mattress (72”). The quilt pattern is crappy enough that even if you don’t repeat any fabrics in the borders, it can look planned. And with stars, half square triangles and log cabins in the center, you have lots of options. Friendship or sawtooth stars, flying geese, half square triangles, piano keys or string pieced strips. Grab some graph paper and have fun with it!