No Four Seasons on the north shore, or Oahu, for that matter.
That said, if you just stay at the Four Seasons hotels while in Hawaii, you will be doing well.
Four Seasons Hualalai on the Big Island is fantastic. Best hotel in the islands.
On Kauai, we stayed at the Grand Hyatt. Very nice, but also going to likely have many families. Princeville may be a little more adult-oriented.
For Maui, we have only stayed at Kaanapali. It is a busy part of the island, with just about every hotel brand on the beach and lots of food/drinks/shopping. The Four Seasons in Wailea is supposed to be very nice.
One option you may consider is Lanai. It is slow, with only a few hotels on it, but they are very nice. We stayed at the Four Seasons Manele Bay and enjoyed it a great deal. Excellent golf and you can take a boat over to Maui, if you choose.