I thought that ever since about 2014(ish) all Macs went into full hibernate mode after a specified period of uninterrupted sleep (called the Sleep Delay). Something like 70 minutes for laptops I thought. Am I mistaken?
The new iMacs actually are also set to do this automatically overnight I believe. EU power-saving directive.
Nope, no hibernate until near when the battery dies (at least by default).