I recently returned from a backpacking trip to Newfoundland's Gros Morne National Park. The park is a part of the International Appalachian Trail and is on the Western side of Newfoundland. The terrain is low mountain and is arctic tundra so a lot different from much of the places I've camped.
There are two back-country routes there (trails is the wrong word). The North Rim is a linear 27 km and the Long Range linearly 35 km. Despite the seemingly short distance, this was a 6 night solo trip and I don't know if would be possible in much less. The reason for the hardship is that there is no actual trail and the park has this wonderful tree called tuckamore that is stunted balsam and spruce trees that grow in this arctic tundra and are essentially impenetrable.
Having no trails for most of the route, the wardens require you to take an orienteering test before issuing permits and make you take along a transmitter. They also have you trace out a recommended route. Most people follow the Long Range Traverse which has campsites at 5 places and few follow the North Rim which has thick tuck and path-finding is challenging.
My first night was after a short trek to snug harbour, a nice little site sheltered in what is essentially a fjord. After that was the climb to the Long Range Plateau, about 700m above the first site. After around 9 hours I made it to the next site. The next day was another 9 hours of treking up and down and through tuck and bogs. It's amazing to think that walking through knee deep bogs, climbing 100 m up a ridge, or detouring a couple kms was preferable to the tuck.
(Thankfully) the fourth day was rainy and fog dense enough to prevent navigating so I had a day to rest and take in some calories. After that, the way was a little easier when I got onto the Long Range, except for numerous waist deep river crossings and the decent back down which finds it's way down the side of a cliff, dropping at a 45 degree grade (in the rain).
Biggest surprise was that I had decent weather for 4 of the 7 days (the others were rain and thick Newfoundland fog). Some amazing scenery including snow patches, caribou, moose, ptarmigan (and some pretty big black bear prints).
An extremely challenging trek (especially carrying 8 days of food) but well worth it.