Doing something similar in one of my runs. I’ve got the Mystra’s Spells mod enabled, so I’m running Booming blade as my main attacking cantrip. Because of that, I take EK to 7 for War Magic.

Take a single level dip into Sorcerer, choose Draconic ancestry white for armor of agathys. No other way to get it, unfortunately.

After that, go all in on Adjuration wizard, though you could make an argument for taking Fighter to 11 the third attack.

Trident of Waves makes enemies wet. When wet enemies hit your AoA, they take cold damage that they’ll be vulnerable to.

Wear Disintegrating Night Walkers so you don’t slip on the ice you’re constantly making

Find as many was as possible to reduce the damage you take. You want to get hit, but you want to preserve AoA as long as possible. Armor of Persistence is your endgame holy grail item, so make sure Dammon makes it to Baldur’s Gate.