P.O.
I just did this last night with my 4yr old son. He also is potty trained but the nights I worry about too...I bought one of those changing pads at Walmart for older people (or the ones they put under you for the bleeding when you are delivering a child). I let him sleep without pullups and then sleep on that, then wake him up around 2am to go pee). He did albeit in sleep mode and then went back to bed. He woke up dry this morning. I am going to keep trying that and see if I am successful getting him into a routine to get up by himself later. Maybe other moms have other success stories I would be willing to hear too.