In my experience with my 3 kids, you can't exactly "Night train". And really, EVERY KID IS DIFFERENT.
My son ( now 12 years old) potty learned in 3 hours when he was 2 years 4 months. Seriously. Told him in the am that we were going in the potty from now on and that I would give him ONE m&m after going ( he had NEVER had one before....lol), fed him enormous amounts of liquids to give him ample opportunities and by noon, he was getting up from playing, walking to the potty, and going by himself, unprompted. It was NOTHING I did. The kid just was ready, and I caught him in that magic window. He was becoming dry at naps ( cloth diapered child) and that was the actual cue that I thought he may be ready to potty learn. 2 weeks after being dry at naps every single day without incident, we ditched the nap time diapers but stuck with the bedtime diapers. I'd say a month or 2 after, and he started waking up dry on his own, and when he had 2 weeks straight of dry diapers, we ditched those too. He has never had an accident since at night.
My daughter ( now 9) was almost as easy. She was 1 week shy of her 2 year birthday and her older brother was home from preschool sick for the week ( minor sickness) and I thought that since we had the opportunity to be home without interruptions and she had been waking dry from naps, we'd give it a go. We started on Monday, with the same methods above, and by Wednesday she was taking herself to the potty without prompting. She too became dry at naps a month or so later, and we ditched the diapers for good!
My youngest ( now almost 4) was a MUCH different story. I did the same methods, and she was NOT interested. She'd go if I took her, but would NOT go unprompted. I firmly believe a child is NOT potty learned if you, the parent, are constantly taking them to the potty and asking them if they need to go. If I didn't ask her, she'd pee her panties. It was VERY frustrating for me, especially given my previous successes. But, I chalked it up to her stubborn nature, and stopped asking her and gave up for the most part
One month after her 3rd bday, I was sick in bed, and I hear her running to my dh, " I gotta go!" and he took her to the bathroom, and she's been potty learned ever since....no accidents. She became dry at naps soon after and ditched the diapers. She is now almost 4, and she still isn't night time dry consistently. She is starting to have 2-3 dry nights a week, so I'm thinking we are getting close, but it's definitely not the same pattern as her siblings.
For the most part, I think cloth helped. But I'm now not doing cloth for 1 diaper a day.....it's just a pain. We are in pull ups. I reward her with a treat if she wakes up dry, because I was suspecting that she was wetting soon after waking up and just being too lazy to go to the potty. She also just recently stop nursing for bedtime so that may help too. Who knows. But the older two were still nursing at bedtime when they stopped wetting at night. If you aren't nursing, stopping fluids earlier in the evening can help, and making them go potty a few times before bedtime. I have a friend who still wakes her 10 year old to go to the potty around 11 pm when she goes to bed. She isn't really awake....she is half asleep, but used to the routine, and goes right back to sleep. If she doesn't do this, she wets the bed. Its' kinda of like the "dream feed" that breastfeeding mothers do to get a few extra hours of sleep!
Good luck....I"m right there with you.....