On tarmac special stages at night with standard 7.5" 'S' disc set-up and 2-pot standard callipers, running Carbon-Metallic pads and AP600 brake fluid I have actually had the discs glowing a dull red colour, but still had superb brakes.
I really don't know why anyone driving on the normal roads, or on ordinary track days can't make 7.5" or 8.4" discs with standard 2-pot callipers work well at all times.
I believe that 4-pots with vented callipers are only necessary for long-distance racing using sticky slick tyres in the dry on twisty circuits.
The only time I have had brake fade is when testing with poor quality pads, like 'GREEN-stuff' or some other after-market non-branded pads. With the Mintex 1166 or 1177, Ferodo 3000 or Carbon-Metallic pads and good brake fluid there should be ample braking available with plenty in reserve, even absolutely flat-out on twisty and hilly closed alpine roads when driving on full pace notes.