Night nappy for heavy wetter

My wee girl is nearly 5 months old and we have been using prefolds and covers during the day and a sposie at night. She is on a bottle and consumes a lot of milk in the last few hours before bed. I have found that the sposie is leaking by the time she gets up in the morning. Does anybody have any suggestions for a night nappy that may last the distance better than a sposie for such a heavy wetter. Prefolds last at least 4 hours during the day so no issue there really. I have an ecobubs merino nappy which seems to fit. She is quite a long lean bubba with only slightly chubby thighs! I thought maybe a polarfleece cover over a sposie could be my next move?!

I second that!! Designer bums are great!! I use the same combo and have found it fantastic!!

My Sophia is long and lean like yours and Iwas going through the exact same situation as you two mths ago.
I use ecobubs wool pockets with two honeychild inserts or with and ecobub medium insert with a bamboo insert between the fold.
I hope this helps.
90% of the time she does not wet through but sometimes she is beginning to. The nap goes on her at 7pm and comes off around 8am.