Thanks for the comments all, and I agree with the consensus that the more natural look is better. I'm back in front of dual monitors so can have a better go at processing now and will look at some of the single frames to.
I do have some iso 3200 shots which were not nearly as noisy as I thought they would be, and may try and use tem as the sky. If nothing else, I know where to go next winter to try do the job properly
