What is the measurement on the centerline of the quilt?
That is quite a lot to be eased in. it would be about 3/4 inch on each side of center. Are the pieced border units stitched at 1/4 inch? You might go back and stitch a wider seam allowance to take up the extra fabric.
Another tip: Stay stitch the edge of quilt, press, and re check measurement. I also stay stitch all border edges too.
Honestly, I would re-work the border so it fits.