Let me fist mention that there is one at the Palazzo and one at the Venetian (we stupidly walked in the cold to get to the Venetian one at 12am and we were staying at the Palazzo.
The late night menu is extensive, not the full menu but it will satisfy every craving. I found it especially good that they served full meals 24/7 for those who came in on international flights with their stomachs demanding a full meal.