An Update on an impossibility After exhaustive trials over a number of laptops I have established the following tech imbroglio as being an immutable fact of Microsoft life
1. Settings / system / <Power and Battery> leads you to a page which has a rather large garish and colorful battery-level indicator atop it.
2. The first entry is <Power Recommendations>
3. The 2nd entry is labelled <Screen and Sleep>
4. within that 2nd entry there are various selectable time intervals that have defaulted to a minimalized four sections. Two of them are the battery powered options for "screen OFF" or SLEEP (screen default OFF being 3 mins & 5 minutes) The remaining two contain the "when plugged in" options ( for screen Off and SLEEP). These two sub-sections contain a multiplicity of choices. Unfortunately whichever option (including the desired 16 'go to SLEEP' options [concluding with an ever hopeful "NEVER" ] will reliably revert to the shown very time-limited power-friendly default-set's DEFAULTS as soon as you exit "Settings". Programmer has failed to incorporate any SAVE option on that page.
So you can thereby accomplish nothing by way of a selected change,
Why because?, As with the infamous Hotel California Lyric:
"We are programmed to "receive"
You can check out any time you like, but you can never leave"