Sebastian the difference between suspend and hibernation is ...
That's something most of us probably already understand.  But it's the difference between Standby and Hibernate that I asked about.  Suspend is a category in Plasma's system settings, but not a command.
Which DE are you using?  On Plasma, apparently the only way to use Standby is to Sleep first, and that doesn't help me, as I said.  (See the image above.)  The only apparent solution for me is to just lock the screen (META+L).  Although it leaves the computer running, it works, and I don't need to restart 10 different applications in the morning, and try to remember where I was working in each of them.