My approach would be 2x Brazil 12 month codes for £60, turn on (and then immediately off) recurring billing after each redemption. That’s 26 months. Get a 6 month code, on/off recurring again. That’s 33 months. Then your £1 will take you to the maximum 3 years. You’ll lose a month, so going for a 3 month code rather than 6 might work better.
Brazil codes need slight VPN faff to redeem, but electronicfirst has a step by step. It’s not painful. Just don’t start your VPN trial until you have the codes.
Up to you whether it’s worth the extra effort, but it means it’s an option to get 3 years of ultimate for around £80.