Well, in your system you have a prusik brake set up on your main line attached to your anchor. Once the raft releases, your brake is now holding the raft. There are several situations that this could leave you in, and they all have different answers.
One thing that stuck with me at the class I took was to slow down and assess things well before starting a plan. Most of the time, once you are in raft rescue mode, everyone is safe, and it's important to stay that way. Once you have a raft pinned, and there is possibility of more downstream traffic, get a safety person setup upstream to stop river traffic.
Look at your angles, anchors, and note where your raft might go after it releases. You might have to pull river left, but the occupants could all be stranded river right. Ropes in the water are serious, so we need to minimize that risk. Hope this helps
Wishing I was on the river instead of surfing the web...