basic family plan. It's exactly the same as the premium family plan except $3 cheaper and has no audiobook access for the plan manager.
I forgot to do this until today and was just charged for another month of the premium subscription. I don't use the audiobooks. They only made the basic plan available back in June. This was their way of introducing a higher tier while defaulting everyone to it. Add a feature to the only family plan. Raise the price. Then make a new lower tier without the feature, but keep everyone on the higher tier.