IcelandAir offers direct flights from Edmonton, and easy connections from US and European destinations. Return flights from YEG are roughly $1000 return, with taxes included.
It's essential to rent a vehicle. Car rental is pricey, the best deals we've found are SadCars (gently used vehicles, similar to "rent a wreck" in Canada) and Hertz. You get better prices for booking and paying in advance.
A map to Djupavik from Keflavik International Airport is here.
You'll travel on Secondary roads for the last 60km, but not "F roads" – all this means is that you're okay without 4WD (we did our last trip to Djupavik in a Yaris!)
There's a couple of photos of the road to Djupavik above. Hopefully no snow, but you never know!! Drive slow and safe. Stop only in designated pullouts (there is one every Km.)
You'll notice the part about booze. Alcohol pricing is insane. Buy booze at KEF duty free for the rest of your trip, fill your flasks, and save yourselves a ton of money. A $30 bottle of vodka at Duty Free is $80-100 in vinbudin (liquor vendor).
PACK YOUR BATHING SUIT! EEEEEEEE!