Thanks for the replies guys. I noticed on this thread there is a suggestion to run:
sudo grubby --update-kernel=ALL --args=mem_sleep_default=deep
Which looking at this seems it’s where system state is preserved in memory and everything else is powered down. Which is basically what I thought the default would be… anyway, I have seen significant improvements in the overnight power drain (used to be 100% to almost 0%, now it’s 100% to 90% over 10 or 12 hours).
I will try this for a while before going for full hibernation. It’s taking a full 10 seconds to resume from deep sleep so I’m hesitant to go full hibernation when this has got me most of the way to where I want to be.
Thanks for the help!