In my scenario, his supply lines are protected by a 'neutral' Saudi Arabia and a 'neutral' Syria on either side; the actual 'front' through which US airpower could be applied would only be maybe 75 miles wide, which would simplify his defense. Besides, the length of Hussein's supply lines is a function of where his supplies are, and what are we really sure of there?
First point: Fahd & Assad will either (a) be very smart and not notice those US aircraft violating their airspace, or (b) we'll say f*** it and take everyone on. Second point: if we don't know where his supply dumps are (unlikely), we'll know quickly enough when he starts moving. Large columns of fuel trucks are rather easily discerned in Western Iraq.