Is morality found in the golden mean, the middle path, as Aristotle claims (as does the Buddha)? Aren't honorable, but extreme,

The Golden Mean vs. Extreme (sounds like a wrestling match!)

Again, two possible correct answers to the same question. Where is morality found? Back to Wittgenstein - what is the definition of morality? Assuming the most common - doing good, doing nothing to excess (except being good), serving others, choosing the 'right' - I personally believe that morality is to be found in the Golden Mean, yet extreme actions can also be moral. How do I reconcile the two views?

Consider suicide. It is considered immoral by many to commit suicide. Perhaps a soldier throws himself on a grenade and in the process, saves the other soldiers in the foxhole. What of a mother throwing herself in front of a moving vehicle to save her child? Or of a firefighter running into a burning building to save a stranger? These are extreme acts that could undoubtedly result in the ending of one's own life by choice. Yet can one argue that these are immoral acts?