Yes, sorry, this is a limitation in the Houdini Indie license for third-party renderers. The plugins can't export scene files to be rendered offline or in the cloud. I'm afraid that all the Indie third-party renderers have the same limitation. Be aware that Mantra has the same limitation ... from Indie you can't export Mantra IFDs files to be rendered offline or in the cloud, so probably requesting this feature for the third-party renderers makes no sense for SideFX.
You could try to find a render farm service that could render your Indie .hiplc files directly in their system (something that I'm not sure if it is allowed by Otoy, to be honest), or you could try to rent GPU virtual machines in the cloud to install there your Houdini/Octane licenses (something that also, to be honest, doesn't sound easy).
Computer Graphics Software Developer
Octane plugin development and support: LightWave and Houdini