Take all the time you need to get this right, Adywan. Personally I'd be much happier to be watching this in February and knowing it's the best work you could do than watch it in November and know that there were some aspects that you just "decided to live with" because you wanted to get the film done by a certain date. You've come this far -- might as well finish it to your satisfaction.
Also, the trench run looks terrific. I can't believe that, as someone who's seen the film dozens upon dozens of times, I've never consciously noticed the missing trench in the background. The colour in the scene looks good, at least to my eyes. Even if there is any "washing out" of the colour, I think the corrected brightness and contrast more than compensate for it.
Keep up the fantastic work Adywan; you're in the home stretch!