Well, Iran is not really that big, it's approximately France plus Spain plus Germany put together.
On the other hand, you don't really need a lot to launch a strike, especially since Iran did not hold the Naval and Air Domain, you don't need a base to do so, all you need is sub, destoryer and an aircraft carrier.
And if the US and Israel is doing what I think they were doing, you are talking about a Desert Storm style blitz, it won't last forever, probably a few months, but that comes with maximum damage and they don't need to bomb every inch of Iran........