Your best bet is to look for an obvious ravine or depression before the storm hits, but when the cloud is over you, spread out your group at 50' intervals to reduce multiple injuries and assume the lightning position. Naturally wet ground, like damp ground next to a stream, isn't any more dangerous than dry ground, so don't worry about this. It used to be said that wet ground was more dangerous, because it conducted more ground current, but wet ground actually dissipates ground current faster. Neither wet nor dry is considered more dangerous than the other. Standing in water should be avoided.
Dry snow is an insulator, but wet snow is a conductor.
This should make travel on dry snow safer than on bare ground, because it will be harder for a person to generate streamers or conduct ground current. Avoid cave entrances. Small overhangs can allow arcs to cross the gap. Natural caves that go well into the ground can be struck, either via the entrance or through the ground. You should never be anywhere near any metal handrail, wire or cable during a storm.