Go north. Base yourself around Mangonui area, and you can fish all the far north on a day basis. 90 Mile, Tokerau, East Beach, Rarawa, Hendersons, Kaimaumau, Rangiputa, The Bluff, Spirits Bay, Te Hapua, Paua wharf, shipwreck Bay, Tapoutupotu, Brodies, The farm, mangonui entrance, and wharf, Whangaroa harbour,Taipa and Cooks are a few spots to try.
Yep that should do for a week or two, and it doesnt get any better than that.