Dar’a province and the Naseeb border crossing with Jordan are likely to become the Syrian government’s main effort in the summer of 2018; the majority of opposition groups appear willing to reconcile.
Once that is achieved, the rebellion will be largely restricted to Idlib province where Turkey backs Islamist rebels who fight Assad and the east where Kurds and Arabs hold largely along the Deconfliction Line (or DCL, as I call it). The DCL basically follows the Euphrates River.
Barring unforeseen developments (duh), Assad looks like he has won the civil war by retaining the core of Syria in the west and retaining the power to rule it.