Man City will score, and without Kane Spurs are likely sunk, regardless of Son's undoubted brilliance. Still, Spurs have the home shutout and away goal advantage (should they score in the second leg). So even if I am giving them little chance of progressing, I think we could see a very tight finish.
Then again, City could blow them away and I would not be surprised. It is hard or overemphasize just how much of an advantage Man City have over just about everyone else at the moment in terms of money and talent. even in a one-off match it makes a massive difference.