Hence the use of the word "partially" :-).
I wasn't aware that the Bezpopovtsy were still so numerous - from what I'd read they did not endure Communism as well as the Belokrinitsy and other Popovtsy or recover from it as quickly. (Though perhaps that's not the case in the Diaspora?)
There are significant communities of them in the US Northwest (particularly Oregon) and Canadian West (Alberta and British Columbia, most notably), as well as some in Alaska, Brazil (a few smaller communities elsewhere in South America, as well), and in Australia (a Popovotsy friend in Oz, describes the community in Sydney as fairly large).
In Eastern Europe, as well as those in Siberia and the community that my brother, Michal, references in Poland, there are also communities of various sizes in, at least, Ukraine, Romania, Latvia, Estonia, Bulgaria, Belarus, and Georgia. There are Bespopovtsy in England, but they are scattered and unorganized according to an Old Rite hieromonk whom I know there.
As regards how well they endured Communism, they definitely suffered and suffered horribly, but the isolation in which many of them (particularly those associated with the Stranniki and other 'Isolationist' sects) lived in Siberia, and in the taiga generally, afforded them some measure of survival. In some respects also, the lack of presbyters and the fact that some among them worship in house churches, rather than more typical stone and mortar temples, undoubtedly afforded a measure of invisibility that was not as available to the Popovotsy.
You also have to keep in mind that the degree of formal organization among Bezpopovtsy varies significantly - from those whose worship is structured and communal to those among whom it is a very individualized praxis that may involve only an immediate family or a few families within a remote village. These considerations make any effort at a 'census' very difficult once you leave the confines of the two or three largest bodies.
As an example, Skritniki (Hiders) were first documented in the mid-19th century. They shunned all contact with secular society, either living in huts deep within the forests or wandering wilderness areas with no fixed abode. When forced by authorities or circumstance into more conventional environments, they isolated themselves to the maximum extent possible. Some subsisted nocturnally and others even perceived isolation as essential to salvation.
The sect was thought to be extinct by the early 20th century but, in 1978, geologists working in the taiga came into contact with the Lykov family, who had then been living in near total isolation for a half-century. Agafia, the youngest (and sole surviving) member, would now be in her 70s, I believe, and was still alive a year or so ago. She remains there by choice, despite various efforts to resettle her with relatives who were located or with other Old Believers; she has, however, made some compromises with total isolation.
More recently, around 2000, census takers accidentally discovered a remnant community of three elderly women in a remote, otherwise-deserted village of the Komi Republic in the Urals. Despite being the sole inhabitants, they ventured out only at night and did not socialize, even among themselves.
As memory serves, I posted a series of 4 or 5 posts to a thread here a couple years ago, in response to a query by an individual who identified himself as seeking to become a modern-day Stranniki (Wanderer). One of the posts was devoted to listing and discussing the variety of beliefs and praxis among the Bezpopovtsy, although I don't think that I got into the particulars of which and how many might be found in various locales in modern times.
Edit: On searching, I find that, while I discussed Bezpopvotsy in the thread I referenced in the paragraph immediately above
, I didn't append that series of posts here at OC - probably because the OP in that thread was not much for dialoguing and it got a tad contentious. (I did post it at Byzcath and at CAF at times in the past). If there is any interest in it, I can resurrect the text and post it here or can provide links to it (at least at ByzCath - I don't know if it survives at CAF or not).