Some (funny) sources list Saturn-V payload as 140 tons on LEO :) so according to this logic to get to orbit one has plenty of margin. And as soon as the payload

Some (funny) sources list Saturn-V payload as 140 tons on LEO :) so according to this logic to get to orbit one has plenty of margin. And as soon as the payload is in orbit it uses full value of accumulated speed, so it's used to get further and getting to the Moon is no harder than with Earth...