I hiked in Auyuittuq 16 years ago. August is the time to go. I agree with what was written above. The valley is stunning. 4000 foot rock faces, glacial moraines etc. We had about 15 hours of daylight and lost about an hour in the 10 days I was there. The arctic flowers were out in bloom in the return trip to Pangnirtung.
You should consider a tour, is it was difficult to arrange cheap boat transportation to Overlord at the head of the fiord, and even more so to guarantee them to pick you up. The wind is definitely a factor, and there are no trees , so a sturdy four season tent is a must. If the tent blows away the only shelters are the very small radio huts every 10 miles or so.
I actually saw more people there than on some of the hikes I have done in BC a few hours from Vancouver, so if you are trying to escape people you can probably do better in the central coast or Southern Tweedsmuir/Chilcotin area of BC for a lot less money. But I digress. The arctic scenery is stunning and definitely worth a visit.