I started a thread ages ago about this but can't find it - sorry for the repetition!
Dd is 5 this week and still in nappies at night - not ready for going without at all. We have had real problems finding night-time nappies that are big enough to fit her (she's in age 8 clothes, so they need to be pretty big), and absorbent enough to cope overnight. We've been using some Libero ones that the lovely MTPW sent me and they have been great, but can't buy these anywhere, and I'm running out - so could do with some recommendations of larger nappies to try.
We had her in Pampers Easy Up nappies before, and they just don't cut the mustard. Someone also recommended Pyjama Pants, but they didn't do the trick either - I think they're more like training pants, and they weren't up to holding all of her wee.
Someone, somewhere must make a nappy to fit a larger child that won't leak at the first sign of being wet!