Have a great ride! keep us informed!
sweet bike,i have a Trek 7000 (a model down from yours)
after trying everything, i happen to like white lightning (wax based) to use as a chain lube because it runs clean! your chain talks to you when it needs more, thats it... apply it, wait 5 to 10 mins, and wipe off the excess.
but if youre using oil now and want to make the switch after all the good things youve heard about wax based lube, youll have the remove ALL the oil with degreaser (simple green on some paper towels wrapped around the chain with your hand while back pedaling it with your other hand)
and then rinse it with some water, and hand dry it before you can apply the wax, because they do not mix.
Oil based chain lubes work fine too, it just picks up ALOT more dirt amongst other issues..
If I were you i would also apply white lithium grease in a few particular contact points so that they do not ever cold seize.
pedal threads, seatpost shaft (inside frame ofcourse), and threads on any other parts you might want to readily replace in the future.
DO NOT put grease anywhere on handle bars!
and if you want to keep your frame clean through this ride, ive heard a quick spray of WD40 on the down tube allows dirt to be easily wiped off.
but heres the link to look at winter tyres
im not sure of availability in or around iceland, but if you plan to buy them here, thats a different story.
as for your shoe question, what do you have now?
Lake makes some nice winter cycling shoes, there are many ways to keep the feet warm, and if you want to cheat, get a few of those cheap hot packets.
.. but you probably know how to dress being from the icelandic region.
as you should know DO NOT WEAR COTTON SOCKS, go with wool/synthetics instead because it still breathes and insulates even if saturated. cotton will just compress and freeze. ick.
the pearl izumi neoprene shoe covers look cool, but i use totes rubbers... same thing.
as for the fork, it should be fine but you can get the lizard skins for it if your so inclined on keeping your fork pistons clean (which is a good thing)