Well, your intrepid adventurer is definitely having an adventure.
Judging by the number of people with very bad teeth, Vitamin C is not a real high priority.
Traditionally, however, there was indeed a significant amount of berries in the diet (I asked Emily Karetak and Napatchie MacRae, confirmed by a hunter from Pond Inlet named Roger). Caribou stomach stew was greeted with a round of "eeeewwwww"s. If anybody ever ate it, it was dropped immediately upon other foods being available. On the other hand, unborn caribou calf is still quite the delicacy, especially among the elders. Nice and tender on your five teeth, you know.
Meat is still the staple up here. It looks like there is a serious health issue for the Inuit these days, in that they are not eating anywhere near the amount of country food that they used to, but eating a semi-western diet instead. And very meat-heavy at that. Not a lot of vitamin C in a burger and fries, and since an apple is $1 and a candy bar is 75 cents, guess which they eat?
And just for your information, the Frobisher Inn in Iqaluit offers an Arctic Sampler plate, which consists of frozen raw caribou, arctic char, and muktuk. I’d try it out, for the sake of the Straight Dope, but I’m running out of money and that’s too much to spend on something I’m pretty sure I’d think was yucky.