The person who didn't rage quit should not be locked out of queuing for 5 minutes just because their opponent was a jerk. If my opponent quits, I'll take the win and queue again against someone else.I think a 5 minutes cool down time for any disconnection to the game is reasonable.
If your punishment idea is only supposed to punish the person who disconnects, and assumes that we have all the tech needed to detect that with confidence, then standard leaver penalties deployed in most games would be more effective.