No, I was thinking more about the Amur valley and Northern Siberia being a lot warmer during the Ice Ages than it is now, present temp on the level of the Ninth Bolga of Hell.
The Gulag Archipeligo mentions that prisioners working in a mine in Northern Siberia struck an "Ice Lens" full of frozen fish, which they ate with no harm to themselves. This and the frozen mammoth thing started me thinking that there was more to the Ice Ages than people are willing to admit.
OI don't think 'they' know any more than has already been published. I don't think anyone is keeping a secret.