I posted this on the console gaming pass thread. Replace Brazil with whatever version is cheapest for other countries:
I was going to get a subscription for my kids for Xmas - just ran through the instructions here and it worked an absolute charm. The steps have been posted before, but here's what I did exactly to get it, and save anyone browsing back through the thread:
1. Purchase 3 x 12 MONTH XBOX LIVE GOLD MEMBERSHIP BRAZIL from cdkeys.
2. Grab the keys and put them in notepad.
3. Download the tunnelbear VPN client and connect to Brazil.
4. Redeem the 3 keys, one after the other on:
https://redeem.microsoft.com/
5. Disconnect from the VPN
6. Go to here:
Upgrade Your Xbox Live Gold Membership to Ultimate | Xbox
7. Upgrade it through that.
8. Go here to confirm all is good:
Microsoft account | Services & subscriptions
9. Turn off the automatic renewal from the same place.
That was it - completely issue free. Cheers to everyone here for saving me an absolute fortune