Ps there are definitely yidden in Washingtonville. Theres a family I know that lived in BG and they moved further up. They had to be evacuated when the wildfires were going on right after pesach. I also know another family that lives on a huge property in Washingtonville, but they have to import minyan every shabbos.
So they live isolated. It wasn't an option for us.
OP Washingtonville is a 5 minute drive to Blooming Grove and BG is a 4 minute drive from the end of KJ.
So you'll live like 10-12 minutes to center of KJ if that's a plus for you.
Its like Monsey Spring Valley and the beginning of Airmont but unlike Monsey the areas surrounding Monroe attract Satmar people mainly.
There are at least 3 litvish yeshivas that I'm aware of.
(Rabbi Munk's being one of them)
One yeshiva is actually a 30 minute walk from Barns and when the yeshiva is there for shabbos it can be used as minyan.
I used to live in Washingtonville. There really isn’t much of a community there though Bloomingrove, an extension of Kiryas Joel, is on its way to extend to there. There are a few litvish yeshivas for minyen, and some people walk to the chasidic shuls in Bloomingrove.
If you’re looking for a right wing extension of Monsey then Pomona / Stony Point / New City kind of areas might be more relevant.
Monsey is a far way from extending to KJ. I don’t think it’s even possible.
