You just have to remember Anna that I do most things in miniature but that doesn't mean you have to. I'm most comfortable with 1 1/4" or 1 1/2" than I am with 4" or more LOL
You can make these shortcut blocks 12 1/2" if you so choose. it's all about the size of template you use.
When I first posted my methods on the QB in 2009 a friend of mine took one of my quilt blocks and made it into a 24" wall hanging she hung in her hallway. It is very flexible size wise. you are not locked into any particular size unless you are making a key chain or book mark etc.