I think Israel will bomb the SA-10s before they have them set up and operational.
It might be hard to even find a mobile system before its up and running, see the Desert Storm Scud hunts or the mostly unsuccessful vehicles hunt during Allied Force.
I'm sure their Pantsirs will be bodyguarding the S-300s as well.
This would be the first time in 40 years that Western forces would have gone up against would have gone up against major air defense technology of the same generation, other than a few (technically compromised) Rolands in Desert Storm and a handful of SA-13s in Yugoslavia.