Tony wrote:

There's the other point: isn't glide range extended in a 172 if the
prop isn't windmiling?

Yes, but you will lose a lot of altitude slowing down to get it stopped.
Empirical experiments show that, if you're lower than about 6,000' above your
target landing point, you're better off trimming for best glide and letting it
windmill.

George Patterson
Drink is the curse of the land. It makes you quarrel with your neighbor.
It makes you shoot at your landlord. And it makes you miss him.