If you like the jelly roll, carefully cut them down to size. If you don't cut them, you will have to use a larger seam allowance to compensate for the extra 1/4 inch. I personally would cut them. How many are the incorrect size? If too many to cut, maybe find yardage of another fabric and cut your own 2.5" strips to replace the ones that are wrong. Just my 2 cents!
Welcome to the board and happy quilting!