If the Christchurch one is anything like Auckland you don't need to worry about taking the kids by yourself. I found the set up was really well thought out and even though we were about 15 metres from the stage we could see absolutely everything and the guys actually came up into the stands to say Hi to the kids at one point.
If you are near the front they have a nice space between the first row of seats and the stage for the kids to get up and dance along.
I am so jealous - I wanna go again!!!!