Depends on the MOSFET, of course. Some MOSFETS will run up to 300°C, according to the manufacturers.

https://www.digikey.com/product-detail/en/HTNFET-T/342-1091-...

Used in e.g. turbine engines, instrumentation in oil wells or mining operations, and industrial process control. You can get microcontrollers that work in similar temperature ranges, “in any architecture as long as it’s an 8051”.