I have 7 week puppies also and it is difficult sometimes. I get a 7am howling too.
There is always the one who screams the most. I try to ignore her but after 10min I usually give in. I have a seperate area for potty also. They were all doing really good until I expanded their play area. I am trying to get them to go potty as soon as they wake up and 10min after they eat. I have the same problem as you, 2 of them use the potty area and 2 of them go anywhere.
Good Luck to you!