We have a smallish freezer on the front of our boat. It's main job is to hold ice for the beverage coolers (which are Yeti's). We probably still go through 20 bags of ice in a week.
Not sure how much draw the freezer runs, but our inverter and six 12-volt batteries keep up, and everything is still working after 12ish hours without power.
My daytime solution is to bring about 200' of extension cord, and my two Yamaha 2000is inverter-generators. They are hauled up shore when we park, and hidden behind a boulder. They are started in the morning when everyone is up, and then shut down at night sometime before bed. Quiet enough that you don't really notice them when you are on the houseboat during the day (although we don't spend much time on the houseboat during the day), and fuel efficient enough that they only use about 15 gallons of gas during the week. I am sure I don't need to run them as much as I do, but it is nice to not have to worry about power.