Good trip report. Your trip was the same as mine Wellington - Sydney. I am based in Wellington and travelled to Chicago in PE - return - on virgin last September. Since I wanted the Sydney/LAX leg on PE, I had to book PE the entire way. Only lounge access you get with this is on the trans tasman sectors. Really nice, and I hope they don't drop access to lounges. Virgin PE is the most comfortable way to travel to Chicago at the same price as qantas or Air NZ economy.
It didn't occur to me to drink till I dropped. Maybe next time.