Get yourelves a army of velonasaurus and get armies of them on right and left side of the titan,put all of them on turret mode and a Yutyrannus behind the armies and put it on courage mode and they'll do enormous damage to the ice titan
Has to be summoned from a terminal in the snow cave. Entrance is just outside the northwestern part of the snow dome, near a river. Be prepared for a fight, as the cave is chock full of bears, yet is, and other high level dangers
With the release of Genesis, the Magmasaur offers a frost immune buff to creatures in the immediate area when fully charged.
My recommendation (as this guy starts freezing everything halfway in) is to keep one around if possible in the fight.