My suggestion is to connect the CuBox via Ethernet and enable the wireless AP feature in LE settings. Now connect your phone to the AP and complete the Hotel's WiFi registration process; the Hotel should see it coming from the Ethernet MAC, and then you're done.
I have spent some great December days in the sunny Canary Islands with mild equatorial temperatures, and I took a CE client device which connects to my LE server, and I did not think of the alternative of booting the device with android only for the Hotel's WiFi registration process.
I ask for your opinion: Sometimes there is no ethernet connection in hotels, if the LE device supports another operating system (android, windows, linux, ...) to be used in the Hotel's WiFi registration process using the same hardware and the same MAC Wi-Fi, my question is: do you think that once registered with android or another operating system it will work well with LE?