[rlh1957]

As said it depends on how much power your fridge consumes. There are newer low power models coming out every year. Not sure how well they keep up in hot sweltering summer heat.
On 12V DC power, every light that’s on, indicator light burning draws some power.

Lets say you just ran your fridge, no TV or other power accessories, no sun to recharge the batteries, no AC power used through inverter, inverter turned off as it draws power sitting there.
So you’re just keeping the milk and drinks cold… 12V fridge probably runs for two days.

You can gather all the operating power draw from everything snd figure up a rough power consumption sheet or easier yet…
Driveway camp.
Easy in the drive as you are at a base as back up.
Test your rig out.
Remember boon-docking, every-time you turn on the water, shower, flush or wash your hands your 12V water pump runs.

Driveway camping is a great way to test your rig systems out.