Disconnecting from the pedestal when a storm is eminent is plain old common sense. Obviously the likelihood of taking a direct or even nearby strike is low even in active lightning areas (like Tucson during the Monsoon).
The electrician who installed the heavy duty commercial grade surge protection system on our home said that actual strikes are not the main concern. The subsequent power surges that follow a strike in the area and can come long after the strike cause the majority of the damage. A good surge protection system, be it on a home or an RV, will protect from this type of damage and is one of the best reasons to invest in a quality SP. :C