For Assad, the situation is sufficiently clear. Actually, they must try to finish Daesh, and taking as much of the Daesh-held territory as possible. After this, they will find the parts of the territory held by Hatesh, former Al Qaida. Hatesh seems to be the winner in Idlib, that means, they can liberate at least large parts of Idlib. The interesting question is what the US will do after Daesh is finished: Follow international law and go away, given that the only legitimate reason, fighting Daesh, no longer exists, or if they will start to occupy parts of Syria.
I would guess that if Trump continues to rule at that time, they may slowly go away, if Hillary takes over not. But Trump is too unpredictable, he may also start to occupy. Politically this would be stupid, the probable result would be another low scale anti-American war, remembering the Vietnam war. There would be parts officially controlled by the Syrian army, with Russian air defenses, and there would be the illegal Kurdish controlled part defended by the US. Wait for some Arab tribal fighters, together with some split in the Kurdish forces (they are not at all a very unified force) in a local civil war on that part. In this game, these officially local fighters would get the same support which the "rebels" have received from the US and Saudi Arabia. And this support would in this case not even be illegal from point of view of international law. And there would be US troops killed by these local insurgents. Not really a good idea for the US. But, of course, who knows - the US plays a similar stupid game in Afghanistan already many many years, and does not even want to stop it.
If the US, instead, goes out and leaves the Kurds, they have no chance for a separate state. They will understand this, and accept some reasonable autonomy.