I've been freezing whole (peeled) bananas to then cut up for smoothies. So you can cut them up either before or after freezing. If you are in a hurry at the 4 hours before mark...
We don't have any of the creamsicle molds, so I'm wondering about making single serves just in 1 cup plastic containers. Then they'd be like the little tubs we used to buy as a kid, with the wooden sticks to eat it with. Did you have those or was it a NZ thing?
I think that this would work just fine. I made a larger glass container of it, that I could just lift out and cut slices off as I needed it. It will freeze well in any container but it does freeze hard. I prefer to let it thaw a little bit (5 minutes) before serving it, just because I personally like the texture a little softer. :)
It is a great base that you can flavour anyway you want to.