Madara waited for the day when Minato was on a mission to have Obito go insane, otherwise Minato would have solod Obito, the Mist Ninja, and Madara all at once
Itachi was already mostly blind at that point and wanted Sasuke to kill him to try and save him.
OT: Madara was pretty helpless at that point, so Minato had a chance against him. But he definitely understood Minato's abilities and knew that if he was present he couldn't have succeeded since none of his subordinates could handle him.