PM me if you need any advice or info regarding Greenland and Iceland, I work there and have done several ferry flights from Greenland to Europe on B222.
You should have no problems getting Jet-A in Greenland at airports and heliports (Avgas is not so easy to find) and I have some positions where emergency fuel on drums is located.
There is a B222 operator in Greenland with plenty of experience with them, so you should be able to get assistance and perhaps spare parts there.
Iceland has B206 operators and experienced people on the B222 and in Faeroy Islands there is a B212 operator.
AirAlpha A/S have designed a ferry kit consisting of two 200ltr fuel drums and pumps, excellent kit and will give you good endurance.
The U model has 935 ltrs internally if memory serves plus 400 ltrs that gives you 4:15 in the "U" model.