simplewebrtc – Is webrtc good for more than 100 connection?

i have project that im going to use webrtc in

In my project i have about 500 channel and about 8k users in the app

some channels have 500 max connections
and
some channels have 70 max connections
and some have 40 max connections

in each channel there will be one person or two people speak in microphone
and all the other users will just hear them without speaking in microphone

can i depened on webRTC?
and will that be really expensive on me?
do i need TURN or STUN or ICE server exactly?
i want it to be 100% successful connection and medium voice quality