Finished the first Naxx wing (8/8) used shaman to down all 3 heroic bosses no Alexstraza or freeze mage needed.
Key to beating Maexnna is getting minions that summon another minion, healers (witch doctor and farseer), taunts (feral spirit, defender of Argus and earth elemental) and AoE. I had one lightning storm in my deck and used it to gain board control, I also used knife juggler to synergize with my summoning minions.
Deck used for final heroic boss: