I think there should be a way to choose how many days you hunt in a area (with higher days having increasing chances of encountering more and more monsters) We all grind certain areas and i think it would add a neat little aspect of people challenging themselves on how many days in a row they can hunt.
As a better challenge you can add a status that is like "Tired" or something where after a certain amount of days spent hunting in that area in a row you get progressivly weaker requiring you to go to a different area to rest or consume pills or something