backyard greenhouse

Yesterday we put together the 6x8 greenhouse I received for my birthday. It is aluminum framed and very strudy. I am not sure what to do about the plastic however. We get tremendous winds in South Dakota and last year we had a large snow accumulation. Does anyone have advice on whether I should install the plastic this fall or leave it off for next spring. I was thinking I could save a few container plants longer this fall if it was totally set up, but then would I risk wrecking the greenhouse? I am not sure how strong the plastic really is, after all it is plastic.
Any comments or suggestions welcome. I am so excited for next spring!!