I understand the need to do this for such an event @Anders Gunnarsson, but we only offer this option at this time in Wowza Streaming Engine where you can control the recording segments directly. I’m sorry for any inconvenience.
With a Cloud workflow, it’s not possible to split the recording right now. In Cloud you will need to record and download the entire recording. You can split/segment the recording afterwards, but not during the stream.
Here is the Engine doc if this is an option for you perhaps through our free Engine trial: