Route and aircraft type? What will be your fare class? If it's Y B M on DL, you can use miles to upgrade if upgrade inventory is available. I doubt that this is possible for ANA, although it might work with a FULL Y fare.

Would the ANA flight have Premium Economy as a compromise? DL doesn't but you can pay to reserve coach seats with extra legroom and a few perks, called Comfort Plus, formerly Economy Comfort, and abbreviated here as C+/EC.