[murphyv310]

Hi.
A good friend of mine (sadly passed) did a good few trips to northern Norway (Nordkapp) towing a caravan behind a Skoda 110LS then a 120LS later on. He drove from Livingston via the channel then up.
Conditions could be bad but rear engined cars grip better than FWD if your climbing hills.
He always carried chains but rarely had to use them. The weather can plummet very quickly and can catch you out with frozen brakes, doors that refuse to open, stiff gearchanges and of course a cold cabin.
Make sure you have an undertray, snow and ice can accumulate in areas you don't see, it can get into wiring looms and cause havoc.
If you are going to change the coolant and increase its antifreeze mix I'd be inclined to use the blue stuff as there is some thought that high percentages of OAT can be damaging. Make sure you're matrix is clear, it the outside temperature is -15c or below a blocked matrix will have you shivering in no time.
Lubricate all the door locks, hinges and make sure the drain holes are clear in the doors, lubricate the door seals with glycerine to stop them sticking to the door in icy weather.

Most of the other stuff is common sense.
Enjoy your trip.