I experienced the idea controller in weird state in several occasions too.
I think your best option is for active cooling of the cpu, but if you are comfy with 180mhz and no further effort - totally get you.

I think over 200 you will need hard peltier 12v cooling and that will require massive insulation to prevent condensation. Can be a cool experiment but without space tech applied it will be a techbench experiment, even the rest of the system can take it. I ran 2x80 and while cool, it requires significant wait states which compromises the point.