To be honest I'm not sure what are those rebels doing or hoping for. It's obvious the Syrian govt, will reclaim those lands and no outside help will arrive. They can get support from Turkey, material, but no troops. Via proxies from westerners too, but I don't think they bother much.
So the only place is left is the conference table. But time works for the Syrian govt. The more the rebels wait with surrender the less cards they'll have, the less they can negotiate with.