Ice collects first on small areas, such as window wiper bolts and the like, because small protuberances produce small pressure disturbances ahead of them in the airflow - and small disturbances don't shove aside the supercooled droplets which form ice as well as large ones.
Bigger aircraft have bigger wings, produce larger pressure disturbances ahead of them and so collect less ice. You'll have a lot more of a problem with wing ice in a Navajo or King Air than a 747 (apart from the addition of being forced to cruise in the icing regions for a greater amount of time.)