Ice, studs & tire pressure
Maybe I'm over thinking this but I'd like some confirmation.
A tire with higher pressure would have less surface contact on ice than one with lower pressure.
So the higher pressure tire would have less studs digging in but each stud would have more force so would dig in deeper and give you more traction.
That's why I recently pumped my tires back up to 7psi from 5psi so I can ride in both snow and ice without too much resistance on pavement.