The STM32L series has the lowest power consumption, but the specific model is similar to a series, and the pins are more abundant, and the power consumption is greater. Power consumption and a lot of things related, such as the main frequency (you reduce the frequency of lower power consumption, the manual is generally written not to increase 1M frequency, how much more power consumption), internal resource usage (do not use the IO port will not initialize, do not use the module will not open, etc.).
It is recommended that you choose on the official website, the product is constantly updated, and it is normal to say that this model has low power consumption and will be surpassed by another one tomorrow.