I see the merits of both versions. However, as I take issue with trying to force nature into a pre-determined aspect ratio, I'm open to cropping. In this case, I'll be typically Canadian and split the difference: the crop would include the tops of most trees on the far shore, except the two or three on the left (I would do both and compare the impact). Additionally (or alternatively if you'd rather not crop), I would most likely add a grad mask to the top to help "contain" viewers from drifting up and out of the frame.
Good luck!