As a former sailor, I have an inbred aversion to running a genset. I am getting over it however.
On our recent trip, the longest we went without plugging into shore power was 7 days. The boat has its original 3 x 8D sealed LA batteries for the house bank. We have 5 folks on the boat in very warm weather. No aircon. The 9' NovaKool was working overtime as well as the 12v 2' freezer we have in the cockpit. The inverter was running the sound system (silly, large 120v system big enough for a large home that the PO installed) as well as charging all the phones and tablets. Another draw is my wife's CPAP which would run off the inverter for about 8 hours each night. Then the Kuerig and microwave used the inverter some more.
During that week we didn't run the engine much more than a couple hours a day to get from one location to another. I have the inverter set to cut out if the SOC drops below 70%. I found that I would typically run the genset in the morning and evening for a couple hours each. This would usually get the SOC to 85-90%. Overnight, with the fridge, freezer, CPAP, and anchor light running, not to mention all the kids charging their phones, I could usually make about 3 cups of coffee on the Kuerig the next morning before hitting the 70% SOC cutoff. When running the genset I would also run the electric hot water heater, more for adding load to the genset than the real need for hot water.
I can't stay away from the dock for that long often unfortunately since I am still working, but some added solar would have been really nice. With the unusually nice weather, I think it wouldn't have taken much for it to get the batteries close to 100% SOC by the end of the day. Not that I minded running the genset in the evening since it really is quiet, but it would have helped to get the batteries fully charged daily.