Tricky this one! 85% Torque with 1 on board and 40 gallons might be hard to get on the "back side of the curve". Haven't flown a 206 for a while, it would probably hover OGE at this power setting. A really high landing site might help!
As for the theories of reducing the RRPM, be a little careful going down this track as the TR loses performance much sooner than the MR. In fact the MR on most helicopters becomes more efficient at lower RPM.
And of course as you are thinking about how to extract yourself from this position you are getting lighter!
Somebody got a 206 they can take out and see what the real numbers are?