Not yet, sorry. Houdini 16.5 is only supported in the Octane 3.08 plugin builds, and we don't have the Octane 3.08 Standalone/SDK demo version yet. The good news is that the final release of Octane 3.08 is around the corner, including the demo version, so the release of the Houdini plugin demo version with support for all the latest H16.5 production builds could be a matter of few weeks or less.
Computer Graphics Software Developer
Octane plugin development and support: LightWave and Houdini