Duiring the Vietnam War....a US Army UH-1H aircraft crew found themselves confronted with the absolute worse case scenario of "stuck collective"....that being the collective stuck at the maximum up position.
The aircraft was in the process of taking off from a "Hot" LZ....took numerous bullet hits from hostile forces....and upon reaching a safe altitude...discovered they could not lower the collective.
They were able to fly the machine to an airfield and landed it by means of reducing Rotor RPM. The old Huey with its amazing strength coped with the situation quite well.
As to location of throttles....it is of no matter as the left hand is going to be free to manipulate the throttles and not be required to move the collective. I have done the maneuver in Bell type helicopters and Sikorsky S-76's.
A thing to remember....as you decrease Rotor RPM you will find the Tail Rotor begins to lose thrust as well making the Pedals less effective.
It is truely a balancing act in multiple parameters.