I have Amy Bento's "10 Minute Solution Tone Trouble Zones!" which contains only Dynaband exercises, is at the intermediate level, and is 51 minutes long(ships with a green dynaband). I bought it to use when I travel, but I don't find it very challenging.
You can go to www.collagevideo.com and type "dynaband" in the search box to see a few more and pick one that matches your desired workout intensity level.
I had posted a band workout for travelling around the holidays. If you check under the rotations posts, search for "Travellin' Band". It has a full-body assortment of exercises for use with the bands!