DD was totally potty trained during the day at 22 mths - yep very early BUT she wore pull-ups at night until 5 1/2 yrs as she was such a sound sleeper. Gradually she got better and stopped the pull-ups. I say, why not just let him go to bed in pull-ups and then you don't have all this worry about night-time wetting. If he is not concerned about wearing them, then I say let him and he will eventually grow out of it. If he does not want to wear the pullups them yes, limit drinks 2 hours before bed and cover where he sleeps with a folded towel to catch any accidents. If he does wet the bed, take off the towel and the sheets are dry underneath. Good luck.
8 Years Ago it was just DH and me.
DD(7),DD(4),DS(4) & DS(2)
(now thinking about a dog)