That sounds fine. I'm leaving for well over a year with a 65L, but I pack way lighter than anyone else I know. Go for it.
"All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find that it was vanity: but the dreamers of the day are dangerous men, for they may act their dreams with open eyes, to make it possible. This I did."
-T.E. Lawrence, Seven Pillars of Wisdom