Vettel really deserves credit for this race.
In the first stint, he was faster than Ricciardo, overtook for position, ran him close and did a monster in-lap 2 seconds faster than his team mate. Because of this, he ended up ahead. During the second stint, the gap was roughly 2 seconds between them - possibly Vettel hit his tyre deg issues again at the end of the stint or they just wanted to make sure he does not interfere with Ricciardo. In the third stint, he did a mistake in lap 38 costing him roughly 4 seconds, but after that he was actually pulling away from Ricciardo on older tyres at 1.5 seconds per lap before the safety car came out and after Ricciardo overtook Button (he roughly had 8.5s gap by then from 3s after his mistake).
For that reason, it is very likely he would have stayed ahead of him (the delta would have to change by 3 seconds in the last laps in favor of Ricciardo for him to come out ahead). In case of not having the red flag, Vettel would have been on fresh inters - even though inters were probably the wrong tyre, there is still a significant advantage of having fresh inters on a wet track compared to used ones. Given that he was faster even on used tyres, I think he would have overtaken Ricciardo and might have had a serious shot at more than that.