Our boat came with a 110 volt icemaker. Ridiculous on a cruising boat as it consumed so much energy it was stupid. We pulled it out and installed an Engle 35. The only way to make it work in the same place as the icemaker was to put it on a double set of sliders. When we need access we just unlatch it and pull it out. It looks like one might just fit inside that hole you have.

We loved having the small Engle refrig/freezer and it really didn't take up that much electricity.

From what you say about the way you use your boat I wouldn't worry about power. If you have even minimal batteries for your IP it should be fine, if not just add a bit more to get you through a couple of days and recharge them when back at the slip.