@LI_diva finished sized as designed is 80x80. Is hidden in there on page 2 of the PDF, just above the paint chips. I do prefer rectangular and will probably need an extra row of blocks or something.
@CraftyBecksa Time commitments vary depending on your set up and what she is having us do. Some of the steps, especially at first are doing a kazillion units which often end up in the border. I'd say a minimum of 2 hours of concentrated work on what I call an easy week to 8 hours in a hard. I can usually be done with a clue in one "day" of sewing, sometimes though that is spread out over several days in real life. If you have a 2-hour opening each day, that should be plenty. If not, well -- there is no time limit!
For those of us with established sewing spaces and routines, maybe we can even do something else while we are working on the Mystery. I generally find it is sufficient for me during the time period -- some weeks I have to struggle and push myself. We are after all, making a queen sized quilt in about 6 weeks. My normal projects usually have larger pieces and take about a month.
My friend Barb says she just doesn't understand how even with time zones and such, some people are already done just as she is getting up! Some people are that fast, or are doing half projects, or just get up darn early...