The small front opening type fridges use a bit more power than a thickly insulated boat
fridge. A quick google
search suggests your model is a 3 way fridge (running on gas as well) these use a different cooling
mechanism and use a lot more power on 12v.
Bottom line is your consumption
is what I would expect even in a cool climate with that type of fridge.
A common solution is to keep the fridge off and use it as a pantry and emergancy back up it can be turned on when on shore power
or running the engine
Another thickly insulated fridge is then installed elsewhere.