Dragon Age Inquisition: Killing Fereldan Frostback

My party takes on the dragon Fereldan Frostback, one of the 10 High Dragons in DA:I, in the Hinterlands (Lady Shayna’s Valley).

Fereldan Frostback is vulnerable to cold, so I’m spamming it with blizzards and ice spells. My basic attack is fire which isn’t too effective against this dragon. This is the PS4 version of Dragon Age: Inquisition.