Assumptions as to weather
You are asserting that since there were glaciers to the immediate north, the tempreature had to be colder.
Those glaciers held a large supply of the world's water, and the evidence in North America is that regions which are now uninhabitable during winter were regularly and continuously occupied by paleo-hunters, and were actually warm and dry grass lands then.
Are there European pollen cores, and if so what do they show? The environment the game animals would have needed to survive? Remember that the Mammoth's dry fur had no loft, and was for cooling, not protection against cold.
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