I had quite a big baby - 4.36kg. I only one one prefold & cover (bambino mio brand) for him. I stopped using it at about 3 months even though it still fit him when we mainly used BBH Magicalls in Medium. I stopped using it before he outgrew it as he started weeing a lot more and it didn't last as long as his other nappies.

I'm not sure how many covers you would need. I would like to know too as I intend to use prefolds & covers for this bub. I think I have read 4 somewhere. Hopefully one of the other ladies will be able to answer for us.