i wouldn’t advise individuals freelancing. but in the past, in a disaster of that scale, i’d expect the US government to offer logistical support, for getting water from place to place, or people from place to place, if there were a disaster of this scale. 1/
For any US administration, Iran would be politically difficult to help, and the Iranian government might not accept it. I’d certainly not advise US help, organized or by individuals, if their government doesn’t permit it. 2/