Funny

That would require being able to grow a somewhat light textile plant such as linen or cotton or jute. If Canadian growing seasons are anything like I imagine they are, that idea is more or less a nonstarter because all those need a warmer zone climate enviroment. So you're left with the dense heavy textile that comes from shearing farm animal wools for clothing making. In modern times you can theoretically grow textile indica hemp with cold resistance and short growing cycles, then process it into a softer and somewhat light clothing through making yarn but that may not br part of native indigenous Canadian culture.

Shirt! .... if you happen to stretch your jeans too tightly over your butt, they're biting you through there too.

Never read the book but I do know what being swarmed by mosquitoes means. I have relatives who live further north and I've been there when I was younger. My worst experience was being out in the woods in deep wilderness in July in the mushkeg. No wind, no weather, just completely still air, hot, humid at dusk when the temperature was just right. We made a fire to smoke our tent but it only made it manageable to survive. Outside, I went to do some repairs to a tent and I had to wear gloves, covered head to toe and a heavy hooded jacket to cover my face. The only thing exposed was about a baseball sized hole in front of me ..... the mosquitoes swarmed the opening and nearly choked me. I was only outside for about two minutes to get things done then had to run back inside. An exposed person in those conditions would have probably gone insane.

But those nights are rare, most of the time, there is a bit of a breeze and mosquitoes are transient. Even on hot humid nights for whatever reason, you get a reprieve and the bugs aren't so bad. Most of the time, there is enough of a breeze to manage things and you can use campfire smoke to control the bugs.

It's a completely harsh environment and sometimes I can't believe humans lived there for thousands of years. And it's where my family is from. The same locations I'm talking about freeze over in the winter to minus 40 degree temperatures in February. You can die by mosquito bites in the summer .... and frost bite in the winter.

That was about black flies

Mosquitos have a small sting and half the time their anesthetic works and you don't notice they're there until they're full. And they often only work in the evenings, less at night and a lot less during the day.

Black flies are a flying platform for a jagged needle and jaws to tear open your skin. They don't bite they tear open a hole to insert their needle. They fly during a hot summer afternoon and in the right temperature they'll swarm, drive you insane, make you run like a maniac and eat you as you slowly flail on the ground until you stop moving.

Mosquitos will leave a little pin prick wound, black flies will leave a big welt the size of a loonie and just as hard and if you get caught outside surrounded by these demon insects, the welts will actually merge and harden your skin ..... and they will keep landing to tear open more.

"And the black flies, the little black flies
Always the black fly no matter where you go
I'll die with the black fly a-pickin' my bones

In North Ontar-eye-o-eye-o, In North Ontar-eye-o"

I would rather die from mosquitos than be tortured to death by black flies

EDIT: For anyone interested, here is the National Film Board (NFB) video being talked about

https://youtu.be/qjLBXb1kgMo

(just the sound of that swarm of buzzing black flies sends shivers down my spine)

That's nothing. You should find the animated version...