Can you add sashing in between the columns so that you won't have to really match seams? If you maybe do 1in sashes in between (cutting 1.5in) then after quilting, it shouldn't be noticeable. Normally, I'd do all flannel or all cotton on the front and save the minky for the backing since as you've found, it stretches and frays so much! Adorable fox print, though!