Now this an interesting discussion +rep. I'd say that Tsunade's death would impact Sakura in the same way that Asuma's death impacted Ino-Shika-Cho and how Jiraiya's death impacted Naruto. Sakura will become more stronger as a result by training harder to surpass her dead master so that she doesn't fall victim to death no matter how strong the enemy is.
Sakura might want revenge against Madara so she might actually end up putting up a good fight with the help of her friends and allies. Her beating Madara though, would be the ultimate Plot no jutsu. As a Sakura fan, how would you feel if Sakura somehow trolls Madara?
Maybe Sakura will be the one to heal the kages and maybe even Tsunade. She will have an important role in the war for sure or at least it would be bad writing on Kishi's part if he totally ignored one of the main characters from the start of the series.