I had this happen to me. The fabric was printed off grain but I didn't know that when I bought it. It was a panel fabric with rhombuses instead of squares. I didn't know that until I cut the "squares" out. So, I went to different shops and bought the same fabric...three times! Well, finally someone explained to me that all the bolts in that line would be printed off grain. How silly if me to not figure that out. I loved that fabric. So, I just added extra coordinating fabric to square the rhombus up...and I made that fabric into three quilts.
So, for me, it was important to focus on the design and deal with the off grain issue with either starch or adding extra fabric to square it up. Othewise, the design on the fabric would have been chopped up and that would have ruined the quilt.