I don't have a pattern, but why can't you just add 3 more stripes to that pattern and then lengthen the borders with the same amount? With other words, if you have added 3 stripes that finish 1 1/2 inches you add 4 1/2 inches finished to the borders.(Vertically, that is.) If you want to make the blue field larger, you just add shorter strips. You can do it!!!