The 180mA looks like a typo. The standby current is in the uA range regardless of 1.8V vs. 3.3V (what app note and page did you find this number?)
The AIC3263 (like the AIC3254&6) is very flexible with regards to power consumption vs. performance. A detailed breakdown is available in the ARG, chapter 2.6 PowerTune. http://www.ti.com/lit/pdf/slau475
Let me know if you have specific questions about the ARG or AICs.