That sucks! I would be worried about an infection from what might be in you IC hoses. I would have heated it up again to sanitize, but it might be fine.
If I were you I would brew up another wort and add it to what you have already. Calculate how much extract you would need to hit what you wanted your OG to be and add enough hops to hit what you wanted your IBU and flavor to be. I don't think you'll enjoy the beer if you add amylase, but I guess it could be interesting to see how it worked.