Bit off an odd question there, but I'll answer it. The game map ends after straying just a bit into India. I believe on of the settlements (Sulek) is located within modern day China, at the very farthest Western bit. Anyways, this doesn't really answer your question.

Estimating from just looking at a map with a ruler, Mongolia and EB's map seem to be around 3000 kM apart, or 1864 miles.