Out of everyone who has been hokage, the one thing they all share is they were the ones on the front line during great struggle. From first to fifth, they all have contributed to saving the village as best as they ere able
Naruto is by no means going to die without having become the hokage by the end of the series, For two reasons,
He is by far way stronger and practically a Sannin without ranks or labels and He has already jumped to the front line of war.
If Tsunade happens to get killed by Orochimaru (which Im hoping will not happen that way)
Naruto is the only one who can become Hokage in the general sense even though Kakashi is the one who is Runner up, Naruto has already become the only Genin to reach Sannin lvl .... Were talking Sannin mode, Bijuu mode.,Kyuubi mode..... You really think he gonna be killed before hokage status.... Think otherwise my friend.