User defined availability window

I have a child listing that I only want to be available last minute and the minimum one month is too long. This is because it is an inlaw that I only want to rent if the property as a whole is not rented. I don’t want my low income inlaw to keep my high income full property from being able to be rented. Of course I would rather get some money than none so it would be great if I could set to only be available a week out.