OK, I’ll play with the 23min-1hour timing and see what we get.
I’ll checkout the watchdog api.
For a pretty complete run down of the problems we have with SLEEP_NETWORK_STANDBY take a look at
Can't Get CellularData to Work about message 18 onward.
It started out to be about not getting CellularData (usage). @ScruffR pointed me to use SLEEP_NETWORK_STANDBY, which did make the data usage stuff work but added quite a few wrinkles. Sorry it’s a long thread but there is a lot of detail there.