I am FAR from an expert, and talking from someone that did not use a crate, I still think you did really really well, he is soooo young, and using the other end of his crate is fine I am sure, and he has such a little bladder etc, he can't be expected to go through the whole night without doing something, and if you have decided to leave him now for the night (which is fine, not a critasism) then surely you are going to have accidents in the morning
Our little one is 14.5 weeks, he goes from around 10:15 till 6am, the first thing he does in the morning is run outside for a poo and a pee. Some mornings he still gets up at 5:30, I think it is quite good really
Hey, remember our human babies, poo nappies, night feeds, that went on for months, dogs do get there a lot quicker, I think he is doing well.