I would bet that most people that are doing this conversion (and there are many, this idea has been around for years [0]) are already doing weird stuff for off-grid living, so turning a freezer into a fridge isn't a big deal - the inconveniences are just different.
The article does not mention that a thermostat coupled to a mechanical switch [1] is typically used to regulate the temperature.
[0]: https://duckduckgo.com/?t=ffab&q=freezer+fridge+conversion