So once in a while sewing and blogging can be oh so simple.
You buy the pattern, download, print, tape, add 10 cm in length and cut it out. Find a big enough piece of fabric in your stash that fits the fabric recommendations, cut it out, sew it together, put it on (okay, have a few fittings along the way but in this case no adjustments were needed) and cheer. Because it fits perfectly right off the bat.