How much does a ground blind contain scent? If hunting a ground blind does the wind become less of a factor?

My experience is that it is less a factor in a ground blind as long as you keep the back and side openings closed / zipped. I always figured that where the wind could blow straight through from one side to the other that you increase the risk of your scent getting out there.

So I don't open all the windows, just enough that I have a sufficient view and shooting window

X2

Don't open up a crosswind, leave the winders closed...

X2

Don't open up a crosswind, leave the winders closed...

I agree 100%

Just for reference...last weekend I had a doe and twin fawns at 8 yards, downwind, right at last light...do your part to be as scent free as possible, keep the windows closed that you don't absolutely need, and you may be surprised how well it contains what scent there is

Yup, had 3 does in a Jan hunt last year come out 10 yds from me.

A portable cloth ground blind or wooden blind?

Portable/ pop up

I hunt in far east Texas, and I don't like to be in a box, I have a homemade ground blind subject to the elements. I also like to close, getting deer 10 to 60 yards from my blind. Two things make this work, camo nylon screen material, and cedar chips, lots of fresh cedar chips. I cover the inside and entrance to my blind with cedar chips. I kick them around when I set up in there, and you can easily smell the fresh scent when they are stirred up.
My belief is deer can separate smells far better than we understand, the cedar chips overwhelm my human scent and give them less to work with it, and I think it may even give them a false reading that the human scent they are picking up is farther away.
I grew up hunting in the Adirondack mountains and used pines needles, pine bows even crushed pine cones in the same way, but cedar chips have a lot more aroma.
Everyone has their own experience, but I encourage folks to try using cedar chips and see for yourself how well it can mask human scent or find something similar in your area that you can turn into a spreadable chip like scent cover.
There is nothing cooler in the woods than being ground level and having a whitetail forging just a few yards away, its my beating my heart that will give me away not my smell.

It becomes the main factor imo... really always is

That's my belief as well, that deer can differentiate smells with their nose much like we can differentiate color with our eyesight. Still, it might not be so much overwhelming their nose with the smell of cedar, but making the strong smell of it familiar to that area, since they will be there often.