Even if the Revolution were crushed it would likely result in more home rule for the Americans, probably similar to the Dominion status that appeared in OTL.
I would give the opposite analysis. I've often heard this idea that if the British won the American Revolutionary War the Americans would just become an alt-Dominion, and I think it's very wrong and entirely misunderstands the situation at the time. If there is no rebellion in the first place, quite possibly, but if there is a rebellion and the rebels lose…? I think not. Let me explain why:
IOTL the victory of the Americans humiliated the King's Friends (and I use that as a term for the specific parliamentary faction that held that name) and the fact that British income from British America did not especially diminish, as mercantilism would have suggested, greatly vindicated Adam Smith and weakened old-fashioned mercantilism. If the British win the American Revolutionary War, neither of these things will happen—or, to be more specific, they will not happen
soon. So a Great Britain that has defeated the Americans will be a more conservative Great Britain, and a government very much inclined to be overconfident about itself (the King's Friends
were, crushingly so) and to treat the rebel leaders exactly as they would typically treat a traitor—in other words, outright execution.
Most importantly of all, the American colonial assemblies have set themselves
against the Parliament of Great Britain. (The idea that the rebellion was mainly against the King is an invention of American republican historiography; in truth, the rebels were primarily against Parliament's actions and even appealed to the King, describing themselves as loyal subjects of his who were being unjustly oppressed by others of his subjects—i.e. Parliament—and when the King declined he was essentially abdicating authority to be a centre of loyalty independent of Parliament; the revolutionaries even developed legal theory as to why Parliament had no right to rule them although they were still the King's people.) That's
immensely important, because it detracts from the sympathy for them that might be felt in the generally pro-parliamentary and anti-royal power British Whig opposition. So the likely result of a British victory in the American Revolutionary War is
not 'home rule' or 'Dominion status' or anything of the sort (it's worth noting that OTL Canada got Dominion status as an attempt to keep it from the United States, not because of some natural British trend for gradually increasing autonomy); it is either outright dissolution of the rebellious colonial assemblies or, at the very least, stuffing them full of loyalists. Letting people whom the victorious Britons view as bandits and traitors to their country—
not as patriots of another country like, say, a very great soldier from France or Spain, but as
traitors to Great Britain (the point was that the British
didn't think that the Americans were a nation separate from Great Britain)—remain in power is simply out of the question. The Québécois, to the British, were merely a conquered people; the American Patriots were
traitors, and, if they lost, would be treated accordingly.
Now let us consider the international situation. In the Seven Years' War the British have defeated almost every other colonial power in Europe; they have profited off the hard, very risky work of their Prussian allies and done very little for the Prussians in return; they have antagonised their allies and outraged their enemies by making such vast gains and gaining such vast territories. This is not a sustainable situation; at some point another European war is going to come, and when it does Great Britain will face a coalition of hostile European powers, as it did IOTL (which is the main reason why Great Britain lost the American Revolutionary War—without the involvement of France in particular, the Americans would have been doomed. Pride goeth before a fall, and all that). If Great Britain is distracted by a major conflict in Europe and the American people are as opppressed as described above, what's the likely result?
So if the American Patriots lose the American Revolutionary War, the probable result is American Revolutionary War 2.0—and if that fails (which it very well might), there will be a 3.0, and if that fails then 4.0, and by the time we're reaching the mid-19th century the American population is so high that I'd be really very surprised if they're not independent—as one nation or many—by then.