I finished the top last night!
I had to turn it sideways to get it on my design wall! It is large lap quilt size, maybe even twin size. I haven't measured it yet for exact dimensions. I cut a bunch of squares that didn't get used for the pieced border. I have made them into four patches and will use them on the back - somehow. I used a jelly roll for the blocks and I have a few strips left over that will also go on the back - somehow. And I have a good bit of the blue batik stripe fabric to use on the back, but not enough for the whole back.
I will mark my design wall so that I know how big my back needs to be. Then I just start cutting and laying stuff up there to cover the required area. It's not a very precise method, but it works for me.