This paper presents a family of voltage references in standard 40-nm CMOS that exploits the temperature dependence of dynamic-threshold MOS, NMOS and PMOS transistors in weak inversion to enable operation over the ultra-wide temperature range from 4.2 K to 300 K. The proposed references achieve a temperature drift below 436 ppm/K over a statistically significant number of samples after a single-point trim and a supply regulation better than 1.7 %/V from a a supply as low as 0.99 V. These results demonstrate, for the first time, the generation of PVT-independent voltages over an ultra-wide temperature range using sub-1-V nanometer CMOS circuits, thus enabling the use of the proposed references in harsh environments, such as in space and quantum-computing applications.