As someone said, Thanos snapped away half of the universe and Hulk brought back half. While Iron Man only snapped away Thanos' army which is significantly less than half of ALL living beings in the universe, also that small snap killed him so you can't compare the two.
I agree with this.
This being said, thanos and Hulk do not outclass supes in energy resistance by any means given how neither has anything above a point blank nuke tanking feat, so I'm going with supes being, just like them, damaged but alive after snapping.
If he sunbathes he could just snap, rest a few hours, heal and snap again, why not. he surely isn't dying in one snap or no selling them though.