I just thought of one other possibility.
You can send UDP to the Internet directly from the Xenon. So you could use CoAP or implement your own UDP protocol.
You can read about UDP to the Internet in this post, under the section called “UDP”: Sending data with mesh devices
There is also a guy who wrote a CoAP gateway in the cloud for interfacing with AWS IoT: https://github.com/AndrewFarley/coap-for-aws-iot
I haven’t tried either yet … but they are on my ToDo list … 