C.T.
I don't know if this will work for you, or if you'll even want to try this, but my daughter is completely potty trained and she sleeps 12 hours straight without waking up. She's never peed or pooped in her underwear during the night, but my huband and I both feel that going 12 hours without peeing is too long so every single night I set my alarm clock for 1:30 in the morning and he takes her to go pee. Sometimes she's barely awake, but she pees every time! Maybe that's something you may want to try with your son.