Imo, G5 isn't coming for a little while. Usually Luffy has a decent amount of onscreen fighting with no interruptions before he brings out his powerups. What we've gotten for Luffy vs Kaido since Chapter 1000, is a lot of offhand/offscreened skirmishing, so it's not the same thing.
I'd say if he focuses decently on the fight the next ~5 chapters while finishing other stuff, we may have a chance of seeing G5. Who knows though, I can see him showing off the real tank man finally or a new G4 form. I'd actually love it if he could finally swap between the forms instantly.