I actually have a crazy theory he might be alive in Boruto based on a lot of little bits of evidence that align with the themes from Naruto and Shippuden. Now don't get me wrong, I think his story line originally was definitely meant to be his death, but I'm getting the impression Boruto is starting to begin the process of bringing him back, as the Kashin Koji/leader of the new Akatski organization. Here's the stuff I keep seeing that lines up.

1. As has been mentioned Jiraiya's body has never been found or retrieved after his death.
2. He was never reanimated or brought back, and it seems to me there were several chances to do so. The first is when Nagato revives the Hidden Leaf, the second is when Kabuto and Obito revive literally every other character, and the third is when Orochimaru revives the Hokages. It seems to me you could make the argument that you couldn't revive him because he wasn't dead, etc. etc.

Now with just this I thought no way they'd bring him back, it would trash Naruto's arc and his own, which I still kinda think, but here's the new evidence I noticed.