I haven't been recently, but I go every year mid to late Sept & never need any. Atikokan had lows of 34 & 35 degrees the past 2 mornings. We're headed for Quetico in 10 days and will not be bringing any. That's one of the best things of a fall trip... no bugs. Have a great trip!
I just completed a hike on the Sioux-Hustler trail. There has not been a killing frost yet, so there a a few bugs, but they are very minimal. Really not a problem. Not quite non-existent, but close to it. I do not think you'll be bothered at all.