The spin Hall effect in a heavy metal thin film allows to probe the magnetic properties of an adjacent insulator via magnetotransport measurements. Here, we investigate magnetoresistive response yttrium iron garnet/platinum heterostructures from room temperature beyond Curie $T_\mathrm{C, YIG} \approx 560\,\mathrm{K}$ ferrimagnetic insulator. We find that amplitude (local) magnetoresistance dec...