A colony of Russian "old believers" retreated into the wilderness, interacting with the outside world only long enough to trade furs for fishhooks and sewing needles. They were found (I think in the 1940s) by a Soviet pilot, and forcible integrated into the communist society -- but, Aleksandr Soltzenitsn points out, they had bought for themselves a generation, several decades, of liberty.
The comparison to the hidden villages of Russian Old Believers is an interesting one. A lot of people are criticizing this movie on plausibility but there has indeed been precedent :) Thanks,