Is that actually true? I'm fairly confident my work Mac requires a password if it's idle more than a few days (typically over the weekend).

Settings -> lock screen -> “Require password after screen saver begins or display is turned off”

Even with that option set to "Immediately" you can still use Touch ID after locking.

I am not sure how it works on Macs, but on iPhone, after first unlock after a reboot, it’s trivial for law enforcement to break into your iPhone - the same with Android.

Shift+Option+Command+Q is your fastest route there, but unsaved work will block.