First check to see how Find A Grave has it. I believe the Cemetery project is using that standard.
Second, check regions in Canada:
There currently is not an Estrie region..
I would wait on the Cemeteries project to weigh in, but it appears the Estrie is just that, so my inclination as yours.
Sand Hill Cemetery, Sand Hill, Québec category, and then build from there with:
Sand Hill, Québec and also the cat: Québec Cemeteries