Example. The MCU should wake up automatically every 5 seconds. This is possible with the RTC. But are there other ways to achieve this? (so not using the rtc?) Timers don't seem to work because the clock is turned off. 

To measure the current of the MCU on the Nucleo L073RZ there is an IDD header (JP6), on the Nucleo L552ZE-Q there is also a IDD header (JP5).I expect when I remove the header and leave is open (no current meter) that the MCU does not receive any powe...