I agree with leaving fabric in the largest pieces possible so they are available for the greatest number of options. You can always cut smaller, but making pieces larger is much more difficult. Also, if it is all cut into smaller squares, it is very difficult to know exactly how much of any fabric you actually have on hand. On a personal note, out of all the pre-cut sizes today, I find the greatest amount of waste with 10 x 10" squares so that would be my last choice to cut to. I really like the filing cabinet idea, but be sure to anchor it well. With all that weight in the drawer it could tip easily.