a bit simplistic there. Washington didn't use real guerrilla tactics (that's why I said semi-guerrilla), but he did use maneuverability and avoided the largest Brit forces in the field.
The entire New York campaign saw him going head to head with the main British force.
Then we have Brandywine, Germantown, Whitemarsh and Monmouth.
In other words every battle of the Philidelphia campaign Washington commanded, all but one had 10,000+ on each side, the exception being Germantown where the Britsih only had 8,000.
After that we have nothing else until Yorktown, except Washington besieging the main British force and planning to attack them there.
The only time Washington displayed what you are talking about is Trenton and Princeton which the British left open because their main force was withdrawn a few hundred miles from Washington.
Washington by and large was conventional in meeting his enemy head on in the field except it was quite happy to sit back inactively as well.
A number of times he would have been brought to destruction because of his willingness to stand and fight if Howe had been willing to press matters to a conclusion (Brandywine being a classic example).
The south wasn't completely clear, but with Cornwallis' army gone, there isn't much left... Greene has effective control over the area.
True, but he still couldn't oust the British from their posts (he lost at Eutaw Springs and Hobkirk's hill despite having the advantage in men 1,500 to 900 in once instance) - those 8,000 troops could easily go south and send Greene running back into Virginia.
Even if they don't Greene's army is tied down because if he leaves the Britsih can extend influence from their posts.
As for foraging... the Brits did it more than the colonials did,
That is going to require proof.
and behaved rather badly in a lot of places too... their behavior cost them a lot of good will in Philadelphia and other places.
For my recollection the farmers around Philidelphia were quite happy to sell to the Britsih because the British had gold and not continental script.
Continental script was so unliked that congress had to empower Washington to forcible take what he wanted whether the populace was willing to exchange it for continental currency or not.
Washington's army at the time of Yorktown wasn't racked with mutiny,
No the mutinies came in the winter when troops stood about freezing with little in the way of supplies or clothing.
and with Cornwallis forced into a rather humiliating evacuation, it wasn't likely to be either.
Until winter.
Funding was a constant problem, but with the French on board, it became less so, although it never did completely go away.
Congress had to reduce the size of the army in 1780 because they couldn't afford it any more, even with the French on board.
And the problem comes in when the French can''t afford it any more or decide to drop out.
They had to borrow the money for Yorktown form the Spanish who had to take up public subscription in Havana.
And by the time of Yorktown, the bulk of the population was on the rebel side, not indifferent and waiting for the war to end... you'd have to go back several years to get that kind of situation...
This assumes the populace wasn't vulnerable to war weariness.
As "A few bloody noses" puts it "the vast majority of Americans, [...] hankered after an end to plunder and scavenging for supplies, the return to the rule of law, and the restoration of sound finance for a land where American paper money was almost worthless, inflation raged, goods continued to be seized, and the cause itself faced bankruptcy."
"The cause of independence was probably never less popular than in the spring of 1781".
I would say the mutinies over the winter proved this (the troops had signed on for three years and were fed up with the war - in the end six regiments were discharged entirely, how long before more troops decide they have had enough?) as did the fact that new recruits weren't really appearing any more and the army had dwindled to 13,000 (having lost a net 8,000 over the previous year, 6,000 the year before, 5,000 the year before and 2,000 before that).
A clear pattern is established of diminishing interest in signing up to the army.
Washington certainly doesn't seem to have think the British had already lost,
"We must not despair. The game is yet in our hands, a cloud may pass over us, individuals may be ruined, and the country at large, or particular states, undergo temporary stress” before victory - this was written just a few months before Yorktown.
If the French get a kick to the groin and are forced to abandon the North American coast then Washington would have believed in his own mind that he couldn't win since he said
""Instead of having the regiments completed agreeable to the requisitions of Congress, scarce any state in the union has at this hour one eighth part of its quota in the field, and there is little prospect of ever getting more than half. In a word, instead of having any thing in readiness to take the field, we have nothing; and, instead of having the prospect of a glorious offensive campaign before us, we have a bewildered and gloomy prospect of a defensive one; unless we should receive a powerful aid of ships, troops, and money, from our generous allies, and these at present are too contingent to build upon."
Admitting he isn't going to get those ships would be a big blow.
As far as public opinion is concerned, if the French lose a major naval battle and the British follow up with taking Newport/ destroying Westpoint/ returning to the South (or all of the above) I think public opinion in the colonies will begin to crack.
Should the French withdraw then it is almost certain to be a PR disaster for the rebels.
The troops themselves aren't going to be happy if they march south to no effect and then are forced to march north again, there would certainly be trouble over the winter again.
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