I love this idea of matching I Spy. I have three stacks of I spy squares in which each square has a match. The third stack does not have many matched squares yet, but the first two are ready to go, I think. Thank you for the quantity of squares and finished quilt measurements. That helps with my planning!
For the singles (un-matched squares), I have an idea of laying them out like a road. ...maybe like a candyland game.
Not sure yet....