Well I'm certainly envious. But having daydreamed about Iceland, and having seen the work of others who have photographed there, I have a
good idea of what film I'd take. And with the potential for all that ice juxtaposed against dark rock, I'd opt for a black and white film with a long scale rather than digital. But I don't know what format you prefer... so can suggest anything too specific. If it were me I'd carry a view camera along with TMax400 and Ektar sheet film. With a MF camera I'd probably choose ACROS and Ektar. You can still use your P&S for snapshots; but given the expense of getting to and from Iceland, it would be a shame to be pitifully underequipped to handle the dramatic landscape.