A lot of the great viking explorers were essentially escaping death, having been exiled or been in a feud with some king or other. It could be the same sort of thing.
First the evidence that the Vikings came to North America is quite thin. It's a nice story though. Second, assuming they did reach North America, it should be pretty obvious that North America presents a rather much larger profile than do the Hawaiian Islands. I'm not sure but I think the North Atlantic surface currents might assist especially a trip originating at Greenland. I don't think there are Pacific Ocean currents which would help a Polynesian to hit Hawaii.
ML/NJ