Your Canon should have it. Its called (poorly named to my mind) "Safety Shift" and it changes the iso when your at the edge. Its a custom function.
https://www.dpreview.com/forums/post/22170398
"C. Fn I –8 [Safety shift], is an expanded version of the EOS-1D Mark II N's C. Fn-16 [Safety shift in Av or Tv]. The function [2: Enable (ISO speed)] works in the P, Tv, and Av modes. If subject brightness changes erratically and the correct autoexposure cannot be obtained, the ISO speed is shifted automatically within ISO 100–3200 to obtain a correct exposure. Safety shift overrides the following settings: C. Fn I -3 [Set ISO speed range], C. Fn I -12 [Set shutter speed range], and C. Fn I -13 [Set aperture value range]. During continuous shooting, safety shift might be applied even if flash is used. It depends on the shooting conditions."