Night time solutions

[youngmomma]

So DS is pretty much day trained for the past month or so. I've been putting him in superundies pocket style trainers stuffed with a joeybunz for nights. 4 nights a week he wakes up dry and goes straight to the potty. The other 3 he is flooding the superundies and his bed. Normally between 4-7am is when he floods his trainers.
Not sure what to do....sometimes he wakes up crying, sometimes he sleeps through it and doesn't wake up until after 8am.

Any suggestions on night time training or a trainer that will absorb more?? Not sure what else to do....I refuse to BUY sposies pull ups!