but i don't have enough power sockets for the external drives in the new room
A power bar would probably be your simplest solution.
Is there a device that would allow me to plug in multiple drives from their original location and have them available as network drives ?
To continue using a multitude of external HDDs, you'd need a host device.
Any system that can communicate with the external HDDs and the network should be workable.
Laptop, Desktop etc. I'm assuming they're all USB connected? So you'd need a system with an appropriate number of USB ports and an ethernet port.
Realistically though, now might be the time to consider upgrading your storage solution.
A NAS could be an all-in-one solution here.