difficult to say as it would mean that the side prussia was on lost, the big question would be what would the effects be on britain. Them losing also means that Austria was on the winning side, very likely William V would not have married Wilhemina of prussia, but some other royalty, so he would have found allies anyways.
The big question would be if the patriotten movement would even come into existence because with prussia collapsing what would be the fate of hannover?
Would the british keep a hold of it or lose it? The one i could see that after losing the european battles they would be more forceful (to prevent another defeat) in putting down the american revolt, therefor preventing the patriotten movement to come into existence (at least not in the same way as otl).
France being on the winning side might postpone the french revolution a little.
It all depends how it all started, if it was because the Netherlands decided to jump in on the winning side (with france, austria etc) I could see them trying to annex part of hannover (east-frisia) and the german territories that were more or less dutch speaking, like rhineland etc).
all in all, there is a good chance the patriotten movement might not exist in its otl form if it existed at all.