You'll both love it - just come in january (like now) as it is the best month for weather. december is often fickle, and end of Feb, March we get the odd cyclone (love sub-tropical climates!) and obvioulsy your summer is our winter, so avoid it then.
If looking, place names in the bay are: Russell, Paihia, Kerikeri, Waitangi, Haruru Falls. Any questions on where to stay, what to do, and how much to pay feel free to ask.