In addition to replacing the thermal paste, I was able to lower the temperature of my X1 Extreme Gen 2 to about 40-60 degrees most of the day by:
i) Undervolting by installing Throttlestop, and setting it to launch on startup with Windows’s Task Scheduler [0]
ii) Removing the back panel, holding the fans in place with a paperclip, and blowing the dust out of the fans with an air compressor
I also installed Thinkpad Fan Controller (tpfancontrol) [1] to make the laptop run quieter. After implementing these, the laptop finally ‘just works.’ None of the above was intuitive, though, and I did not expect to find and try these solutions before purchasing the laptop.
[0] https://www.repairwin.com/how-to-start-throttlestop-at-windo...