I believe the fez, as a hat, has some utility in warmer weather as a means of keeping one's head cool in the same way a chef's hat does (heat rises, hence, why a chef's hat is tall and open), and its fairly compact size makes it practical.
I would think that if this were to come to pass, fezzes as an actual fashion commodity would probably come in-and-out over the course of decades (as many things do in fashion), while enjoying fairly frequent use in warmer parts of the United States or as summer wear. In other words, mostly in the same vein of how ushankas (AKA the archetypical "Russian" fur hat) caught on in the colder Northern states.