I would stay there because- well idk

Season 2 ending, after bobs disappearance and the lab mysteriously shutting down

If i had no knowledge of the upside down or the real reasons for everything bad that ever happened,then when the murders started

Probably after S3, At latest when Vecna started crunching kids. At that point with all the strange murders throughout the years I think it would be safe too leave

When teenagers started mysteriously dying looking like that during S4.

After the S4 earthquake, but if it was my home town and i have retired, then i would decide to stay even after S4.