Stevend,
Welcome to TBN!
I used a 42" snow blade on my White GT-105 (20HP) garden tractor for several years to clear snow. Even with wheel weights and tire chains, I found that plowing snow with this setup was tedious. Although it's better than using a shovel, I found that the tractor would constantly drift off-course and get stuck. If the ground is flat, 8" of snow would be close to the maximum ability of this setup. (I also quickly learned that if you are not able to remove all the snow in one pass, the tractor would quickly lose traction). Here in Virginia, it doesn't snow very often, so the setup was "adequate" for my needs. If you live in a region where 8" snowfalls occur on a regular basis I would recommend using a standalone snowblower instead.
My opinion is you could "get by" with using the plow on your garden tractor if that is your only option, but you will be able to clear the snow much faster (1 hour vs 3 hour for me) with a standalone snowblower.
I have never used a tractor-mounted snowblower, but I would guess that it would overcome the traction and lack of power problems that I experienced with the plow.
Please let me know if you have any more questions, and once again, welcome to TBN!
Charles P