We are planning a mostly off-grid Caribbean season with two laptops, refrigeration, a watermaker and occasional induction cooking. The boat currently has 800 watts of solar and 600 amp-hours of lithium. Owners with a similar setup: what is your real daily usage, and how often do you still run an engine or generator?
Start by measuring instead of guessing. We averaged 4–5 kWh per day in the tropics with refrigeration, Starlink used selectively, laptops and a small watermaker. Our 1,200-watt array usually replaced that by mid-afternoon in good conditions. At 800 watts you can make it work, but several cloudy days will expose the gap. I would add a proper shunt first, track a normal week, and size from that data.
Do not overlook shade. We had 1,100 watts on paper, but the boom and rig regularly cut the real output. Splitting the array across multiple MPPT controllers made a noticeable difference. Induction cooking is manageable if it is occasional; heating water electrically was the load that pushed us toward running an engine.
Your battery bank sounds comfortable for overnight use. I would spend money on monitoring and charging efficiency before automatically adding capacity. Solar yield, alternator output and how often you move the boat matter more than the headline battery number.
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