Everyone has there own ideas when it comes to an acceptable level of risk and general well being/living requirements. I reread the OP's original post and this is not a, "I'm thinking about moving to...", that is in fact an "I am moving to... and what do you think" post. This appears to be an after the fact attempt to get some reassurance for a decision that that OP is already be questioning. Clearly, there is a reason above and beyond cultural immersion for leaving a gated community in expat central for the hinterlands of places such as Las Canas, Rio San Juan, Gaspar Hernandez etc.
Based on the phrasing of their post, the OP comes across as a bit of a social butterfly and having contact with expats is important to them. That is easy to understand, but the decision to move to Las Canas then becomes a bit more perplexing. The time for this type of question/discussion is before a decision to move to a remote place is made.
So, no. Las Canas is not a hive of expat activity and the opportunities for finding new best friends is going to be (and pragmatically should probably be) limited.
Next consideration - Loneliness or isolation may precipitate driving back to civilization more often than is necessary. The further out you go, the further you have to drive. The more you drive, the greater the personal risk inherent in that activity. Every time you pull out onto Hwy 5, you do so at some person peril. From accidents, to shakedowns, to breakdowns and all manners of inconvenience great and small, the more you do something the greater the chances of misfortune befalling you. Living far from the comforts of larger towns usually means a large grocery run once a month and local colmado usage for the everyday staples in between. Or at least it should. It would be a shame to prang an expensive car jogging into Sosua for a bag of dog food and a round or two of bingo.
Sit at a cafe on the main drag of Las Canas for a couple of hours and count the number of foreign faces you see. If the total is less than 5, it's a pretty safe bet that there aren't many such people around day to day. I suspect the vast majority would be passing through on their way to somewhere else.
It takes a certain personality type to exist for long stretches of time on their own without a community of somewhat shared interests and experiences. Not being this type of personality can compel someone to be inappropriately friendly or inviting towards the wrong people out of necessity or desperation.
One should consider how long it will take for help to arrive should you need to call for an ambulance, the police, a friend, anyone? Do you have the ability to attempt to outlast any such delay? Can you be self sufficient and self reliant enough to get through loneliness and periods of rain that sometimes wash out roads or bridges that cut you off from the people and services you are used to?
In a nutshell, this is going to be an "interesting" experience for the OP. When a post centres on concepts of loneliness and isolation I would hazard a guess that the OP may not be one of these strong individualist types that will thrive living smack dab in the middle of Dominican culture 24/7. How much additional risk will the "young daughters" be exposed to just travelling to and from school everyday?
Alas, we can speculate endlessly. The decision seems to have been already made and the OP will be able to report back from time to time to let us know the actual answers to their own questions and concerns.
Simply put, expats that are adverse to being isolated cope by not putting themselves in a situation that leads to loneliness and isolation. Some of my earliest posts on this forum detail why I moved to Sosua. It was not for the cultural institutions, the great shopping opportunities or being enamored with the beach. I moved to Sosua because and only because this is where the English speakers can be found in a concentration sufficient to overcome my complete lack of Spanish comprehension and usage at that time. I did consider Rio San Juan as a first place of habitation, but that would have been stupid and I am quite happy that I was smart enough to realize that before committing.
Good luck OP. Please let us know how it works out for you.