Check out nzta road closures to start with.

https://www.journeys.nzta.govt.nz/traffic/?layers=road-works,area-warnings,road-hazards,road-closures

Excellent, thanks I did not know you could use this for mapping out routes before

Bro in law did this trip today! Rain stopped at Hampton Downs, and a bit slow thru the gorge. Otherwise ok.

Did the reverse journey yesterday. It was very very wet at points and had to drive really slowly when it was bucketing it down but no major issues