I think one of the considerations is the taper of the sleeve. You may cut the extra length and then be able to introduce some taper with the underarm seam. The other thing is that if you stitch or sew around the new end of the sleeve, you will need to do it so that you don't create a tight inflexible cuff on the sweater. Here's another idea
(from Ravelry, free to join)which may or may not be appealing to you for the cuff.
The pattern certainly makes a very good looking jacket.