Could see carrying a 400mm with some teleconverters, if wildlife shots were my priority in Glacier.
When giving photography classes or when clients ask me at my shows, which lens should I take backpacking, my simplified answer is, to look at your body of work and see what lengths you most frequently used.
Like taking my 100-400mm occasionally, it allows me not only to take a shot from a distance, but it also allows me to compress a scene, but it only gets brought along, if my project requires it, otherwise it would be deadweight.
My current choice of backpacking lenses are the 11-24, 24-70, and the 100-400 II.
When and if I buy into the new medium format Fuji GFX 100, my lens choices will be a bit limited, but still workable, and having 100 megapixels will allow me to easily print much larger than 8", and still hold up great when viewed close up.
Being at the most optimal location, which may take scouting for hours or days in a particular location, it may also require me to stay 4-5 days in the same basin, and then being gifted with that special light that doesn't happen often, which is why some of my pieces have taken me going back to the same location for 10 years, to finally capture a shot that represents that particular location, and my vision.
So yes, taking my time is paramount, mother nature works on her own timeframe, I have to adjust to her, not the other way around, otherwise I would be rushing and settling for a lesser shot, not being patient and rushing to move on to the next location, which would turn my photos from an art to a documentary style shoot, which is fine, if that was my goal.