I wonder whether there are clock generators with on-chip temperature sensing...
Yes: "an advanced, low-power, high-performance mobile clock generator with four clock outputs. The device integrates a MEMS resonator, temperature sensor and a temperature-to-digital converter (TDC), which eliminates the need for external crystal and temperature-sensing crystal resonators." -- https://www.sitime.com/products/clock-generators/clock-gener...
Yes: "an advanced, low-power, high-performance mobile clock generator with four clock outputs. The device integrates a MEMS resonator, temperature sensor and a temperature-to-digital converter (TDC), which eliminates the need for external crystal and temperature-sensing crystal resonators." -- https://www.sitime.com/products/clock-generators/clock-gener...