User blog comment:Zippertrain85/"Why the Empire Should Prevail Over the Stormcloaks! Part 3 (Economics)" Refuted/@comment-1822253-20140107032124/@comment-1600847-20140107180059

Could very well be. The Imperial armies were attacking from the North-West, North, and North East initially. That left the south open for several days, a straight march to the Dominion lands in Elsweyr and Valenwood. It could be a portion, be it small, medium or large, was able to escape.

It's all speculation, of course, but since we have no proof for either side speculation's all we have.