Fridge

Hypothetical question, If you're fridge/Freezer wasn't working on gas, could you link the inverter to the EHU, or direct to the fridge ( my one has a 2 pin plug and socket behind the lower vent ) did anyone ever do it.?

I did that a few years ago, while parked up in the camping area of Le Mans. The fridge stopped cooling on gas, the burner was severely corroded.
I didn't have a hook up so I ran an extension lead from the inverter to the 230v plug of the fridge.
The 200w of solar covered the demand by day although the leisure batteries suffered when the sun went in.
The botch job saw me through for four days until I got the problem sorted.

Going to 12v would require a bit more detailed rewiring, also there is no thermostat control in the 12v mode so it's continuous running versus 230v which has thermostat control so uses less power. Both 12v and 230v heater elements are rated at similar wattages.

Why bother

Or a fridge full of spoiled food, and going home early, as was the option for the pair in the Hub last week, with no power and then no fridge, they had tripped a a main Switch,and didn't know to bleed the gas trough to all the appliances, after changing the gas bottles. Also my one not working great, so when servicing my burner, I started thinking of a work around.
As @baguette said it could keep you going,