I love this idea! Just posted it myself as I too struggle with a full Owlery! This is my topic, which is the same idea: https://feedback.worldofpotter.eu/communities/1/topics/1295-organize-owls. You can combine it with this one. 

https://feedback.worldofpotter.eu/communities/1/topics/326-add-folders-to-owlery

Just found this topic! Upvote, upvote, upvote!

Hi Meg,

You can send this request to the Minister of Magic of the particular WoP site you are on. They will be able to help you further! 

Kind regards,

Vienna