I use https://owlbear.rodeo/ for that. It allows you to cast your map to a 2nd screen in player mode, while you can still see the full picture. It has ‘fog’ to hide areas from the players and supports zooming in on each screen separately, or you can sync zoom&view (manually or continuously) from your dm screen
I’ve run ‘Sarah…’ as a oneshot too, and even though I got the pacing totally wrong the first time, I agree that it is a good one; I will definitely run it again .