That seems a harsh judgement. It could have been successful.
Then the by then lost provinces would have been returned, and perhaps Estonian would have been two standard languages today, instead of one, since the Russians scorched earth policy did heavy damage to Dorpat/Tartu that was the centre of South Estonian.
The reduction of the noble estates would have continued and serfdom ended in Estonia and Livonia. Courland would have been Swedish.
What lost provinces? The only province the Russians had taken 1707 was Ingria, through taking Nöteborg and Nyenskans, and that was what Peter wanted to keep. Reval (Estonia), Riga (Livonia), Kexholm and Viborg all fell 1710. Before Poltava the Swedes had only lost Ingira to the Russians.
I don't doubt very much that Carl would get cocky and decide to jump in to that mess. IIRC, Marlborough (?) was sent by the English to gain a promise that Carl WOULDN'T get involved - which shows they were worried about the possibility. Plus, Carl would weigh in on the French side (most likely), and he DID toy with the idea of supporting the Jacobites just because.
No, I seriously doubt Karl XII would join the French - both Karl XI and Karl XII were heavily in favour of the naval powers (England/Britain and the Netherlands) after France treated Sweden as a secondary/vassal nation in the peace of Fontainebleau 1679. Getting entangled with the French had not gained Sweden anything but grief since the 30 years' war.