"You can't be in politics for that period of time without being a real reservoir of knowledge, and having a really good understanding of what has worked and hasn't worked in a political environment in the past."
The musical's re-opening is set to be one of the biggest worldwide since Covid-19 forced the closure of the West End and Broadway shows.
The cast of the musical performed two songs for Ardern – who was recently portrayed as Poppins in the satirical BBC comedy Spitting Image.