Suggestions on widening quilt top please

[bonniebella]

I making this quilt for my son. I want to make it wider but not longer apart from the border which will be blue. I have none left of the small feature panels, as I only had 6 which I got from a lady at my quilting group. I was able to buy a bit more of the orange, blue and red in the big panels. I have the equivalent of 23" x 45" in scraps left from 2 1/2" wide up to a 10" square. I have about 1/4 yard of the grey.
Any suggestions for making the sides? I am thinking about 6" or half the size of the other panels.
Does this all make sense?
I don't know why the photo flipped on it's side.

Thanks in advance.