A good question.
A local answer.

Combine South Bank's riverside paths with one nearby gallery, garden or café stop rather than leaving the city every day.

Choose the closer option if you value a relaxed visit and time for Brisbane itself; choose a larger park if its full-day exhibits are the goal.

Look at the current forecast and water conditions close to the date. Air temperature alone does not tell you how comfortable swimming will feel.

If the buffer works, focus on South Bank or one river-ferry segment near a direct airport return route.

A suburban centre suits a broad indoor retail selection and straightforward parking. Check current shops if a particular brand matters.

Compare the boat's departure and return times with a bus or car route, especially if you want a full day at the sanctuary.

Compare daily travel times from a central hotel with the cost of a larger rental and parking. A cheap distant stay may consume the week in transfers.

Check the current ferry route map because not every wharf is served by every service. Plan from the exact wharf names.

Check luggage storage and checkout time if embarkation is later in the day. One relaxed neighbourhood is enough for a short pre-cruise stay.

Consider a guided nature day for places with poor last-mile transport. Compare actual time outdoors with the time spent on the road.

Check the airport's current overnight access, lounge hours and shower facilities directly. Do not assume an old forum description of a lounge or terminal is still accurate.

Base each part of the trip near a useful station or tram stop, and avoid changing accommodation for every attraction.