I was captured by the same thread; I was particularly looking forward for any material on how/if their language diverged from the general population's. Over this long span of time, even in such a small group, do they end up speaking a dialect?
The Lykov Family have been well-covered. VICE had a decent piece covering the sole remaining member: Agafia. Their speech did somewhat devolve, and children born out in the taiga had developed their own cooing pidgin that they spoke to each other, IIRC.
Couldn't find material on that, still looking