Okay,

Frost is working so far, the real trick is to have the Elemental frost nova ready as soon as you cast blizzard.
Oh, and I am at 479 Bonus Damage.....need better gear lol.
For example first courtyard:

Pull
Ice Block
Frost Nova
Summon Elemental
Blizzard
Immediately have elemental frost nova ready (they break pretty quick in Blizzard.
Blizzard
Cone of Cold
Frost Nove
AE
AE
AE
Then mop up leftovers/runners

I make it past the first and second courtyard (be careful to be certain you get all mobs, have had a pat kill my boys several times, even in the corner, stupid huge aggro range ;-))
However the first half of the Cathedral keeps getting me, I think it is more a timing issue there, I am still working on it.

I will say, if you don't have elemental nova ready, don't be surprised if you die....