I did chart the pattern out and you can make it wider by adding multiples of 8 stitches then just following the pattern. There are six pattern repeats across the rows as it is written, so to make it wider cast on either 66, 74, or 82 stitches. The 74 stitch cast on should make the scarf approx 1/3 wider than the pattern as it is written, and the 82 stitch cast on should increase the total width by about 50%. (It will be slightly less than these percentages since you don't add to the border width.)
Good luck and if you have any questions ask again.
It is a beautiful pattern. I might make it for my teenage daughter. It would be a nice wrap for a prom dress.
What yarn are you using?
P.S. Enjoy Saturday - I wish I could be there!