We were considering heading to Rotorua, but opted for exploring the Coromandel Peninsula more. There are limited amounts of places you can freedom camp (park the campervan for free overnight). Many district councils in NZ have limited the places you can park overnight without getting a fine! Since these were the cooler months and far less people were out traveling, we didn’t have any issues finding good places to stay. Tairua has beautiful beaches and scenic backdrop of islands and mountains. Hot Water Beach is only around 30km away and definitely worth a visit. The car park for Cathedral Cove is less than 15km from Hot Water Beach, so all easily accessible. There is around a 45-minute hike to Cathedral Cove with a set of stairs at the end if not taking one of the boat tours or water taxis (video and drone footage below). We ended the trip staying just north of Thames at a freedom camping place right on the water for our last night. The star gazing was great, especially considering we were only around 1 hour drive from Auckland, which we did the next morning to return the campervan. Overall, a campervan is a great way to see different parts of the North Island.
Tips: I would recommend planning your route ahead, or at least familiarize yourself with the freedom camping options if considering travelling by campervan. The amount of places allowing freedom camping is dwindling and if you are paying lots of money for the campervan plus having to pay for the campgrounds or motor parks each night, it might even be more cost effective rent a small vehicle (spending much less on petrol) and stay at backpackers or motels.