Assuming the scenario happened the first bombing runs would be over after 2h and would continue for the next 48h until amphibious assault fast response finishes landing, by which time it’s safe to assume there isn’t much left to defend (though rubble makes a horrible war zone for the attacking side).

Cuba simply isn’t Iran. They’re a blockaded island with not much military experience. Iran is a huge mountainous country preparing for war for the last 40 years with first hand experience of getting blown up from above and from the inside by USA allies and surviving just fine.