Nice solution, but with the case I linked, my Pi idles around 37, and reaches 50-ish (both degrees C) at most (if I load it hard), since the case is sucking heat from all chips and bottom of the PCB.
edit: I replaced the thermal sticker for thermal paste, not sure if that could have affected it, the paste wasn't the conductive kind.
[1]: https://www.amazon.com/GeeekPi-Aluminum-Heatsink-Raspberry-I...
The room the Pi lives has a wool carpet, too.
[0]: https://www.amazon.com/GeeekPi-Aluminum-Raspberry-Cooling-Th...