So Reflectix foam is only about R 3 per inch and its about 1/3 inch thick so around R 3 for three wraps. Closed cell urethane is about R 6 per inch so a 2 inch space would give you R 12. To get that you can buy a cooler which already has 2 inches or more of foam in  it. Ignore the fancy brand name, look for the foam, and don't forget to check that the lid also contains foam. Or, here's a DIY way to do it :

The ices chest performs every bit as well as the high priced brands that cost over $200 or $300.  Here's a link I found for it today.  https://sunnypetra.com/index.php/lifetime-55-quart-high-performance-cooler-grey.html?utm_campaign=gs-2019-07-05&utm_source=google&utm_medium=smart_campaign  Lifetime products, if I'm not mistaken, are made in Utah, which I think is still part of the USA.

I started the earlier mention of using a cooler.   Olddawgsrule is correct --insulation is the key.

I said that we used a quality cooler-it is an Engel , but the best part is that I made an insulated cover for it. I used REflectix roll insulation

https://www.lowes.com/pd/Reflectix-R-21-33-3-sq-ft-Unfaced-Reflective-Roll-Insulation-16-in-W-x-25-ft-L/1014123

which is available at Lowe's. It is 1/4" bubble wrap that is faced with reflective foil.  I used three thickness of the wrap.  Lowe's also has a special foil tape for joints at the seams.  The top can be taken off and leave the bottom in place.

We have kept ice as long as 9 days-we freeze it in gallon jugs and put i jug at each end. Makes good cold drinking water also.

 

hope this helps

Vann

That, on it's self, is a good idea to get through the passage. I like!

As much s everyone is talking about technology and what could be better.. I go back to basic's. Insulation of the unit. 

Every style, type, cycles according to how well it is insulated. Loss of cold and retaining. What do you wish to give up in looks to keep things cold? 

In another group folks have build coolers from HD/Lowes structural foam that far out perform even the YETI coolers. 

Though it would be difficult to line our existing units with such, making smaller boxes to fit within is not. 

My mind goes further, as you now expect from me, and look at building my own frig and using the parts available. 

What I say is not just think of system, yet think of insulation as well. 

I'm attempting to figure out my Wife's dream of a draw frig and how to implement. Would require 3 different draws of 3 different temps.... Yes, she does challenge me! 

And I do so love a challenge!

 

Insulation... My 2 cents. 

A pricey option for times like that is a Free Piston Sterling Cooler. Ours was a different brand but looks the same as the one in the link except for the end caps which are blue. These are very efficient and will operate on 12V a long time without running down the battery. The one we have came from our local ReSTORE. It was donated by a drug company (I don't know which one) and was used to transport medications (no biological/radiological ones)by drug company representatives. It cools to 4C, even in 90F weather. It isn't silent, but it isn't really noisy either. Unfortunately, the Coleman model is not available and I could not find any others that specified FPSC or FPSE except for a FreeBird model which is a deep freezer and priced way beyond anything I could or would pay.

Having a small battery operated fan inside the refrig also helps keep it’s temp when not under power.Refrigerator management is a little different from the home, but it getss easier and a system will evolve after a few trips.

Vann

Think of your frig as an upright cooler and work accordingly. Ice blocks in zip-lock bags (near the beer) and work your produce according to how it want it stay cold. Like I say, an upright cooler. Dry ice to me is a over-kill and not really needed. I did that on a 6 day canoe adventure that I packed some steaks in a small cooler with dry ice. Night five they were still frozen.. Over-kill for a passage.

Don't over think it, yet think it. Ice blocks will do you fine. Packed around the beer, LOL..

We have traded in the 179 for a 195.  The 195 has a two way refrigerator -- either shore power or propane.  When we had the 179 we had a battery option to run the refrigerator.  So what does one do when traveling by ferry when you don't have propane or shore power??

Okay, this may not be a problem when going to Vancouver Island or back but the ferry ride to Newfoundland is 6-8 hours for the shortest route or 14-16 for the longer route.