Which pattern did you purchase?
Squares are usually not a problem, but if the strips are long, that can be an issue. I had one quilt that had a bunch of 10.5" long strips, and the pattern was designed for 42" usable WOF, but I only had 40" so I could get three with a lot of waste and didn't want that. So I cut my strip at 10.5" long and then subcut that.
Anything you need enough of that you can cut WOF - do them and then you'll only have to deal with the leftover pieces.