Diapers for over night

My son is 7 months old and we are sooo close to him sleeping through the night. The problem I’m finding now is more often than not by the time morning rolls around he as leaked out of his diaper and his pajamas are all wet. He has been sleeping on his side or stomach recently and I don’t if that is part of the issue? Everything collects in the front of the diaper and eventually has nowhere else to go so it leaks out the top (That’s my theory anyways). So - any recommendations on overnight diapers??

He’s currently in a size 2, I wonder if sizing up for nighttime would help? We’ve tried Pampers swaddles and Luvs - both had the same result.

Thanks!