Hmm, not easy to say. I heard it can be very light there and in big wave conditions a few extra liters can help avoiding getting into trouble.
But I think you can answer the question best yourself. If you think the Q71 was pretty alright in size and didn't have too much problems on the light days I would surely get a Q74. It will feel a bit floatier than the 71 so it will still be a bit of a light wind upgrade. But if you had serious problems slogging the 71 you might consider the 77.
Personally I'd bring the 74 if I would go the CV (and I'm your weight).