PS i don't think ota availability is region locked.
It is an idea that has been said many times before but from what I have seen the fota server does not block based on your current location or the mobile network you are currently connected to. Those details are sent but I have never seen it block anything you put in those fields.
Fota server does some simple imei checks to release updates in batches and to blacklist certain devices.
It checks model which comes from the build.prop of the rom and must be the correct HTC one x or HTC one xl.
It checks "firmware version" which we would typically call the HTC ROM version.
Most new updates check Cid which must be valid for that ota, eg carrier Cid of supercid.
That's about it.
Details about the radio, the current time and a bunch of other things are sent but do not determine if your phone will get the ota.