The word "ex temporary" means "improvised" or "spontaneous." So, its antonyms would be the opposite of those meanings. Some possible antonyms for "ex temporary" might include "pre-planned," "premeditated," "deliberately crafted," "calculated," "meticulously prepared," "well-rehearsed," "carefully orchestrated," or simply "prearranged." These words all suggest a great deal of thought and preparation went into the activity, rather than it being a spur-of-the-moment decision. In general, the opposite of "ex temporary" implies control and forethought, rather than relying on instinct or chance.