Moving into, exploiting, and surviving in such cold
areas requres tech and hunting. They didn't wear
fish skins to keep warm.

https://www.nature.com/articles/s41559-023-02318-z
Published: 31 January 2024
Stable isotopes show Homo sapiens dispersed into
cold steppes ~45,000 years ago at Ilsenhöhle in
Ranis, Germany

Abstract
The spread of Homo sapiens into new habitats
across Eurasia ~45,000 years ago and the
concurrent disappearance of Neanderthals
represents a critical evolutionary turnover
in our species’ history. ‘Transitional’
technocomplexes, such as the
Lincombian–Ranisian–Jerzmanowician (LRJ),
characterize the European record during this
period but their makers and evolutionary
significance have long remained unclear. New
evidence from Ilsenhöhle in Ranis, Germany,
now provides a secure connection of the LRJ
to H. sapiens remains dated to ~45,000 years
ago, making it one of the earliest forays of
our species to central Europe. Using many
stable isotope records of climate produced
from 16 serially sampled equid teeth spanning
~12,500 years of LRJ and Upper Palaeolithic
human occupation at Ranis, we review the
ability of early humans to adapt to different
climate and habitat conditions. Results show
that cold climates prevailed across LRJ
occupations, with a temperature decrease
culminating in a pronounced cold excursion
at ~45,000–43,000 cal BP. Directly dated
H. sapiens remains confirm that humans used
the site even during this very cold phase.
Together with recent evidence from the Initial
Upper Palaeolithic, this demonstrates that
humans operated in severe cold conditions
during many distinct early dispersals into
Europe and suggests pronounced adaptability.

"Cold temperature conditions and an open
grassland or tundra environment for the LRJ
at Ranis match the faunal spectrum which
includes cold-adapted fauna such as wolverine
(Gulo gulo), reindeer (Rangifer tarandus),
woolly mammoth (Mammuthus primigenius) and
woolly rhinoceros (Coelodonta antiquitatis),
with reindeer being the predominant herbivore
taxon."