Is the husband obligated to return to complete the remaining nights of the agreement after his travel, or does he have the option of establishing a new three-night stay?

A husband must be just between his wives regarding nocturnal lodging. If he is absent from one of his wives due to travel or imprisonment, or if he is unable to spend her entire night, he must compensate her for the remaining nights as soon as he returns or his excuse is no longer valid. This is the view held by Ash-Shafi'i and Ibn Qudamah. Furthermore, the wife with whom the husband traveled by drawing lots does not forfeit her turn due to the travel; rather, the husband must compensate her for it upon his return.