Other than Sakura being the number 1 candidate to die, Sasuke and Konohamaru comes close second which would be my best bet. Whether Naruto dies or not, he holds almost no significant impact on Sarada because I have yet to see a close bond relationship between the two. Ever since Gaiden, Both of them barely interact each others whereas with Boruto, we see that Sasuke spend alot of time with his student and we also see Tsunade despite as a hokage, she tended to look after Sakura.
We know Sarada looked up to Naruto but she has yet to show any sign of getting to his attention or asking Naruto for favor and right now we already over half way point to finish the first part and still nothing happen with Sarada as a character.