BeerMe...
We keep a couple of bags of ice in the side by side refridgerator freezers on cats without any problems. I think it actually makes them work less hard! Not really a problem getting down low, only a couple of times a day.

What else are you going to use the feeezer for? Ice cream!?

And if your cat has a genset, no issue of it using juice. The cats designed for charters are speced for this use. We love the R&C cats, maybe not the best long term cruising boats, but great for short term charters.