I love the way the vignetting complements the composition. If I was going to change anything, I'd mask out the branch at the top left, it seems like it intrudes and upsets the balance for my taste.
Makes me glad I live somewhere warmed by the Gulf Stream!
I know what you mean about the branch. I chalk it up to the chance a Holga induces. I'm really not even remotely "second nature" when it comes to the difference between the viewfinder and the frame. With a Holga, aside from the obvious parralax issue, the frame is simply much larger than what the viewfinder shows. I'm needing to get bolder about composing much closer to the subject and trusting that I'll get it all.