I think Peckish is correct, if you watch the video,the border had a lot of left over scrap. I just came across my twister tool with partially finished blocks from a class I took last summer and just finished them a few weeks ago. I checked my bin of scraps, and the border, just like in M* video had a lot of scrap left. I hope it works out for you, cute pattern, looks like fun, can't wait to see it finished.
I guess if you wanted to pull some scraps to template the smaller size as you posed then you would know if that was possible or not. I have only used the tool in my class and then to finish the blocks a few weeks ago, so I do not have enough experience to answer you question pertaining to making them smaller, sorry. I do have to add though, it was a fun tool to use and plan to use it again as I rather enjoyed it.