The Iranian military is very decentralised and designed specifically with American capabilities in mind. So am not sure they would collapse. And a defending force is far less dependent on logistics in the short term. Also, Iran has a culture of sacrifice.

Iran and the US exist in a state of equilibrium of opposite strategies. The US is unwilling to risk its troops and sees sacrifice as weakness but otherwise applies maximal pressure. And Iran is willing to sacrifice its citizens and sees that as noble. And outside of a black swan event there is little hope of change.

Each side sees its enemies greatest military strength as a moral weakness and will keep fighting. Whilst conversely believing that sacrifice/maximal remote force may someday work. Iranians are not going to pivot because their culture has been forged as a response to exactly this kind of pressure. Nor will America suddenly see the sacrifices of thousands of it's men as virtuous. So things probably just revert back to the same equilibrium.

The point is that America blowing up power plants and Iran absorbing casualties is just an extension of the status quo.