The problem with recuing calorie intake is that it can also lead to lethargy, where you burn even less calories, and reducing intake even more means you arent getting vital nutrients.
You're not reducing to zero. I IF most of the time and have the most energy before my first meal of the day.
That's not wrong but often not that drastic. Reducing NEAT (non exercise activity) on reduced calories is person dependent and can be quite significant.
The body however is quite robust. For a healthy person, there's no acute risk associated to significantly reduce the calories intake for a few months. You should take care to have a balanced diet, of course.