Tiwai Point shutting up shop

[harm_less]

The problem looks to be getting Manapouri's generation to the North Island where most demand is located. Bigger transmission lines?

IDK, it could still supply most of the south island anyway. Im not sure how much capacity the HVDC link up to the north island has, but I know it has been upgraded with a new cable across the strait, and the old cable probably could still be used if they wanted.

This would seem to be the inside info from Transpower. Long story short, completion by Winter 2023:
https://www.transpower.co.nz/news/transpower-seeks-input-clutha-upper-waitaki-lines-project