Info on a Tiffin Allegro Breeze

We are looking at moving from a class C to the Tiffin Breeze 31BR. Our major concern is that most of the ones we see on line for 2017 or 18 is that they come with a domestic refrigerator. Since the majority of our time is spent in national parks w/o shore power or in boondocking situations, what alterations have people made to meet the electric requirements of this fridge? How long do you have to run your generator daily? How much solar is needed just for the fridge? Or should we look for a Breeze with a RV fridge already built in? Thanks for your feedback.