Have Peter stay with the army at Narva a few days longer and get captured or killed with the rest. There, you are done. This Russia isnt the rus of 150 years later. They do not have a huge population to draw on and they are a poor shithole. They have space making them hard to conquer and they have Peter which is a giant trying to pull an entire country up the hill of modernization. Remove him and they are done for a generation or more.
Fun fact everyone seems to forget all the damn time. The commonwealth has as big a population as Russia at the time and is a hell of a lot richer...probably of a factor of 2 to 3 and yet noone seems to bother with them being any sort of threat at all.![]()
Capturing or killing the tsar does put the Swedes in a good position in regards to ending the war, but I find the idea that the Russians have Peter and no one else in regards to leadership (not modernity, leadership) a bit much.
As for population: Did they really have such a large population? Russia (in 1700) has - according to the Rise and Fall of the Great Powers - 17.5 million people. That's not an endless horde of Russians, but I think Poland-Lithuania is half that - maybe richer, but smaller.