I may be wrong but I think Gault (Texas) tops Topper, the one on the Savannah.
The ice in the north Atlantic was 3,000 miles of desolation from France to New York City and up to the North Pole
Not even a volcanic mountain island top. The animal zones would have only extended a couple hundred miles from either shore. An impossible trek in my opinion. Even with the clothing and technology of today.
Certainly not enough survivors to establish a continent's worth of people very quickly.
I don't know the vintage of the bow in Europe or Asia, but it shows up in the Americas about 1,500 years ago from what I have read?
Gramley is in this link--
East Wenatchee Clovis Site - Wikipedia, the free encyclopedia
I have been taken with some early Triangles from New England.
Zuma