I wasn't really sure how much I was going to need to do for winter. I was thinking of making triangles about the size of the opening with brackets like the back of a picture frame but if temperature isn't an issue than I'll just save it for rain cover. There's 1 ft of overhang but the storms we've had recently I know would blow it right in. The baby coop I'd draped a towel over vents the rain would blow in but I don't like it too much since big gusts of wind blow it up over the top sometimes, I need something that will stay put.
Wow. You must get some serious winds to blow rain in with a foot of overhang.
Where, in general, are you located? (You can put it in your profile so people can give more targeted advice).