If the Saudies are willing to let the IAI operate over their airspace then this mission is certainly doable. The Iranians have an obsolete air defenses and the IAI should be able to operate quite effectively over Irani skies. But for logistical reasons it would greatly reduce complications if the IAI could fly tankers over Saudi Arabia and the Golf.
There are alternative routes like over Jordan and Iraq or over Syria and Kurdistan/Iraq. Lets just hope that the Chimpanze in chief at the white house doesn't try to shoot down Israeli sorties over Iraq and the Golf. I think there is a very low chance he would do that for the simple reason that he wants to get re-elected.
It is also conceivable that Israel will have based some fuel tankers in Eritrea or in Kurdistan or in one of the CIS republics (Georgia) for the attack. That will make it possible to circumvent SA from either north or south in case it is unwilling to cooperate.