I have a KZ Sportsmen 5th wheel that has the 12volt Danfoss compressor. It will use about 4.5 amps while cooling and cycles the compressor on and off depending on the temperature you have it set at and the air temperature in the camper. With the average temperature of 78 degrees outside, it will use about 60 amp hours per day.
I like it because when I turn it on it takes about an hour or two to cool down. I also like the idea of it running while I am driving down the road. The downside is the daily amount of Amp Hours it uses, but with the correct amount of battery/Solar capacity should not be an issue.
Our camper was available with a 9cu ft. NovaKool. I wish I had gone that route instead of our 2 way ammonia absorption fridge. We have the solar and battery to support it. If it goes out one day we will definitely make the upgrade. If you are going to go electric as the sole means of refrigeration you will need to consider how you will generate the needed added electricity as Ed mentioned. That includes what you do on multiple cloudy days if solar is your primary source of energy or how much you want to run a generator. You may want to increase the size of your battery bank. If you normally stay at parks with shore power you should be fine with just a couple 6v batteries even for long travel days.
One other comment is that food will stay cold in a fridge for a while so depending on how long you are traveling and how hot it is outside you may be fine to just shut the gas off and turn it back on when you arrive.
We traveled for many years with the gas cooling the fridge. It's personally not something I worry about. I read through our Dometic manual and couldn't find any warning other than gas should be shut off while at the gas station.
Gordy, we've had experience with several 12V refrigeration systems in past "RV's" (sailboats which we lived on for years at a time), including a component system made by NovaKool. Offering summary comments about the practicality of 12V refrigeration for an RV is difficult as a unit's performance is dependent on many variables including box size, whether you're trying to include a freezer section (which usually requires a holding plate), amount of insulation, ventilation of the compressor unit and, not the least important factor, whether the unit offers a water cooling option using a loop to/from the water tank. I can assure you the more battery charging sources you have, the better. A careful energy management study, with multiple 'what ifs' considered, would I think be essential. Personally, I think having the absorption refrigeration option is liberating in that it makes refrigeration available with a lesser penalty of 12V energy management and avoids the weight & expense of the additional electrical support a 12V system requires. But there are advantages with a 12V system, as well. It should be less trouble prone mechanically, and it doesn't care how level your RV is. Another advantage is that small, well engineered 12V units are available off the shelf with a well balanced blend of box size, cooling capacity and insulation. But we're talking shoe box refrigeration choices when compared to the typical RV refrigerator in most travel trailers and campers. As for the 'dorm refrigerator' products (like one shown in the NK webpage you linked), they will be energy hogs and ill-suited for an RV unless it is permanently connected to 120V AC.
So if your refrigeration needs are modest (and exclude a freezer section), you are adept at designing and building up ayour own top-loading box (which I had success with after some research) that fits the space your RV has to offer, and your RV has more than the typical 2 x 12V 100AH batteries plus multiple charging methods, then it could be a viable (if somewhat expensive) option. OTOH I don't think the effort and expense is remotely warranted if you're just trying to avoid turning the LPG on & off when driving.
Hope that's of some help. Good luck with the research and best wishes,