SASless
Yes, a bit over 600 nm.
From memory, Reykjavik-Narsarsuaq and Narsarsuaq-Goose are both about 670 nm.
I don't know the specs of the various R44 models but I assume ferry tanks could be fitted if necessary. (We needed ferry tanks.)
The only tricky part (VFR in a small fixed-wing anyway) of the Narsarsuaq route is that it doesn't have any diversion airfields within range so you have to be 110% sure the weather is OK before passing your point of no return.
It's worth it - Greenland is breathtakingly beautiful. The ice-cap is amazing and flying over icebergs on the approach is quite something.
I agree things could get interesting if the donkey stops but the chances of that happening are minute balanced against the enormous pleasure and great excitement of such a special flight. (Special from a PPL perspective obviously. I look in awe at some of the pictures in the Rotorheads Around the World and Views from the Cockpit threads when I see the places professional pilots fly as part of their everyday working lives. )
As I suggested earlier, flying to somewhere on the East Coast and crating from there is an alternative. For a Brit, seeing so much of America from the air at low level is an opportunity not to be missed IMHO.
FL