Our mini doodle Bentley is currently 4.8lbs at 5 weeks. He is the second smallest in his litter. Mom is an 18lb F2 mini goldendoodle and dad is an F1 mini goldendoodle and weighs 16lbs. Any guess on his expected adult size? Breeder thinks he will be around 20lbs full grown but it seems like he weighs a lot at 5 weeks to be 20lbs fully grown?