Re: Time, gentlemen, please
You forget, Microsoft have past form here with GWX Nagware updates. They can't be trusted to do the right thing on this.
Just use the solution *I* found worked; run a hacked/bootleg version of MSWin7. I had a scrap system I was running the "Evaluation" version of W7 on, and a script that would periodically reset the expiration date for the evaluation. NEVER got nagged to sidegrade to MSWin10.