Hi and welcome leah
no one is qualified here to say if he will go through withdrawal again - that depends on the individual and on other factors like how many times he's detoxed before.
Will he stay sober? that up to him really - its easy to promise the world when you're coming off a binge but much harder down the road when you start feeling good again.
If he's committed to doing whatever it takes not to drink again, he has as good a chance as the rest of us
wishing both of you the best