Since that wasn't close to Cell's full power, he could just bring out more of his reserves until Goku's stamina is completely depleted and the events with Gohan continue as normal. The difference is that, assuming Cell doesn't get a Senzu here, Cell may be too fatigued to birth the Cell Juniors, or at least weaker ones, so in the latter case, Vegeta and Trunks may be able to dispatch two.
Assuming the former happens, however, #16's words to let go may not trigger Gohan into becoming an SS2, as it'd lack the build up of watching his friends almost be killed. If Cell is very fatigued at this point, a resolved SSJ Gohan may be enough to win and due to not having the arrogance of gaining new power, he'd finish Cell off before any Self-Destructs and Zenkais occur, which also means no #18 in this scenario. If Cell's still close to his full power though, the events would continue as normal with the Cell Juniors and the rest of the arc.
Since the former is a more interesting scenario, I may cover it's ramifications for the Boo Arc and perhaps Super, given how it leaves Goku still alive.
As for #17/18, I'd assume Kuririn would wish them back to life after arguing that they weren't evil like those from Trunks' timeline and that the Saiyans and Piccolo would be strong enough to stop them at this point anyway. This would likely be what sparks #18's love for Kuririn in this timeline, with the removal of their bombs through a wish the following year being what seals the deal.