There's an incredibly simple fix for all the potential problems, here, imho and ASTOUNDED that WotC didn't go with it.
Make CdG much more lethal as per various suggestions.
However, make it so that anyone with an Action Point can spend that Action Point to automatically not die and instead merely take the heavy CdG damage (or even "wake up just in time" or whatever, but this works with paralyzed/magically unconscious situations too, where that might not make sense).
Is that not fixed?
All major characters, all solo monsters, all elite monsters (iirc) have an Action Point, so none of them will be auto-murdered. It slightly damages versimilitude if you're going for realism instead of a cinematic situation (where the big bad is never simply killed in it's sleep unless it's already been effectively neutralized).
Normal monsters will still appropriately be dispatched by CdG some of the time, rather than almost universally being able to survive it.
This has the side-effect of making people more keen to press on to milestones before resting, I suspect, as that way they can be assured of avoiding sleepy-murder.