I have a fridge like the one described in the article. It is a cheap chest freezer with this
temperature controller added. I did not buy it to save energy, it was used for kegs of beer back when I was homebrewing. This type of chest freezer/temp controller is very common with homebrewers to allow fermentation to occur at exactly the right temperature. And to serve beer at exactly the right temperature.
I would use this type of chest freezer fridge again. It is far less expensive to purchase a cheap chest freezer plus a controller than a stand up fridge. And then your electric bills are lower as well.
If you were modding a chest freezer the way you plan to mod your stand up fridge, the chest freezer would just get that much more efficient. However instead of 0.1 kWh/day it might draw 0.08 kWh/day.
I never checked the amp draw on my chest freezer fridge.
The best advice I can give is to keep your fridge filled with beer.