I'd honestly be tempted to take the build you have now for just one level. Then switch to Evoker (Admixture) at second. You'll be getting new spells at the same time as you would as a sorcerer (better than a cross-blood) and you apply your bloodline arcana to all spells not just sorcerer spells.
The admixture specialist allows you to change the elements of your spells on the fly so you get more cold spells for your CL boosts and feats to apply to.
Off the top of my head:
Traits: Wayang Spell Hunter and Magical Lineage (both reduce the level of a spell by one for purposes of metamagic)
Rime Spell (+1 metamagic, creatures that take damage are also entangled)
Irrisen Ice Mage might be useful, but -1 CL to all non cold spells is a bitch
Intensified Spell: Raise the dice cap on a spell by five.
Rod of Maximise/Empower: Standard fare for blasting I guess.
if you wayang hunter+lineaged, for example, fireball (and admixtured it) you'd be casting a coldball that entangles anyone it hits and can deal up to 15d6 damage as a level 3 spell. Its not amazing but its not nothing.
Its late here but I'll see if I can offer anything else tomorrow