how to upscale a model helicopter to usable specs?

In the movie ‘the flight of the phoenix’ a model airplane designer uses his knowledge to build an airplane large enough to carry himself and several other people to safety.

I’m wondering about how the same principles could be applied to a model helicopter.

I’ve been looking at an unusual configuration RC helicopter that weighs 1 kilo, and has a carrying capacity of 0.5 kilos. What I’m wondering is how much larger the rotors would have to be to increase the carrying capacity to 600 or 700 kilos.

Furthermore, I’m assuming that with larger rotors and payload, I’ll need to upgrade the 14.8 volt brushless motors. I’d like to keep the whole thing electric, but do they even make electric motors that can put out the kind of power I’d need to make this thing fly?

'The Flight of the Phoenix' was the modification of a full size aeroplane to a smaller, lighter version, not an up-scaling. I have worked with 24v brushed and brushless motors, the brushless being slightly more efficient. 24volts was taken from 2 x 12v car batteries in series. The motors and batteries are quite heavy and very torque-y but not enough that they would be able to spin a large rotor with torque to spare for what you want. At a guess, the rotor would be almost full helicopter size to lift 700 kg.