I am almost through the second volume of Washington Irving's "The Life of George Washington" (5 volumes). The last few pages I've read is where his badly defeated army, after the fall of Fort Washington due to General Greene's foolhardiness, is at the Delaware River that he is about to cross the first time. Most of the few thousand farmer soldiers retreated from their disheartening loss with no shoes, blankets, or tents in the month of December.
It was more daunting than we could ever imagine for the newly independent United States. He had to take on the most mighty superpower of his time. We ourselves are now the most mighty superpower and we have his example to guide us.
So, as you can see our task would be more daunting, as we would face those same things George Washington's army also dealt with, as far as weather conditions go. But they possessed equal fire power, muskets, as their combat opponents had. Sure, they were vastly outnumbered and were up against a far more experienced opponent in the art of warfare, but the opponent had no quick method of enlarging, or even re-enforcing, its presence in a quick manner when troops on the ground were killed in action. They also did not engage in warfare as the British did, and that engagement helped to offset the mismatch in manpower, and experience.
We have none of those working in our favor, but we would be much like George Washington's army in terms of small manpower and inexperience in warfare.