I think it would be a good idea because the non-stop intra-US flights to Hawaii (at least from Chicago, where I live) are always jam-packed. If a plane couldn't go non-stop, one could connect through Anchorage, Alaska or Los Angeles, California to refuel (United flight ### LHR-HNL with a stop in ANC). They could use it with a 777-200IGW
Plus, it would have great passenger feed, as Europe really doesn't have a "tropical island paradise" that I know of (I live in a suburb of Chicago, Illinois and United is my hometown airline, GO UA!!!!). All my images of Europe are that the weather is gloomy, cloudy, colder than average (at least northern Europe). And unless Europeans love cold weather (which no sane person does), Hawaii would be a great vacation destination, even though it is VERY far from Europe.
And I'm not saying that Europeans don't go to Hawaii. A few years back, we were in a restaurant on Maui, and there were people from Germany at the table opposite us.