This doesn't make sense: "With summertime temperatures typically -10°C to -20°C". Maybe the negative was mistakenly added, and nobody noticed in editing? 10°C to 20°C would be reasonable for a "forested and grassland plateau".

it's reinforced in the same sentence after you cut off your quote and is repeated again further into the article:

> Nash said the caves would have been "quite a cosy place to live, especially compared with the -20°C outside".

There was an ice sheet starting just north of this area, it would have melted at 10°C.

Agreed, that jumped out at me also. Those numbers make no sense