We are having this issue, too. My son is 28 months and 35 lbs. He was leaking out of TWO Huggies goodnights! The last few nights he's been in a pinned GMD toddler prefold with 2 hemp doublers and a fleece liner inside of a Dappi XL cover. No leaks yet! He is prone to rash so I've been using Balmex at night. I can always toss the fleece liners if necessary.
He is daytime PL'ed, but floods at night. I've had to make sure I'm really diligent about one last pee before the diaper goes on.