It is mostly a question of priorities.
If the proper conduct of a fast is that important, then time can be found one way or another.
I know many people who take a 4 week vacation just to relax, sunbathe and chill out. If time can be found for this, then I am sure the time to undertake a prolonged fast (if required) can be found.
This was the custom in Sheltons time of people taking their annual vacation in a fasting retreat.