I've been oversampling thermistors with the pin-toggle noise technique for a while now, and that method is solid. But lately I've been noodling around with a new approach that reads therms using the Input Capture Unit on pin D8.
https://thecavepearlproject.org/2019/03/25/using-arduinos-input-capture-unit-for-high-resolution-sensor-readings/This time-based method delivers more resolution than 16-bit oversampling of the ADC, is about 10x faster, AND I get to sleep the processor during the reading. The process is ratiometric, but as with the oversampling, I'm still leaning a bit on the S&H constants to absorb the miscellaneous temperature coefficients from the other parts of the system.
Still, it's another easy high-rez technique that could be implemented on any AVR processor.