Scaling durable workers

I’m new to durable workers, so I’m trying to work out to map current ideas to workers.

Question - How to scale/create new durable workers - in durable speak - how to know when to create new ids?

eg, if I was interested in a specific ‘room’ or event and it receives alot of websocket connections, how would that horizontally scale?

side note: how many websocket connections could one durable worker handle?