It will be interesting to see how this is implemented. I have never applied for an ID because I don't use the iPlayer app. It is easier to just play and download (unrestricted) on the PC. If the site remains accessible but the ID is only required to play something, it may remain possible to bypass the ID and download via the URLs as is presently the case.
I like the idea of the hotel postcode. That is going to be pretty hard to filter out though the license might complicate things. I think a market for spoof IDs will pop up pretty quick, though. Personally, I would still rather give my money to the BBC if they would let me.
I can't see how IP addresses would become part of the equation. License holders, especially young ones, move around and may have different IPs. A proxy or VPN will be sufficient to make it appear you are in the country. More than that shouldn't be necessary.