Given the choice between the extra zoom and the larger sensor, I think I'm edging towards the extra zoom. The reason being most of the time I'm not in the woods and I'm happy to go out only on days with decent light. Over the last few months I've realised we get a lot more sunny days than I ever imagined and so I will have plenty of opportunities and on the days of poor weather I can get other things done, and so I'm happy with that balance.
That option of better quality images in the woods is attractive because there are birds in there I'd like to take decent pictures, but I'm rapidly coming 'round to the understanding that I can't have it all ways with the money I'm prepared to spend!
Trust me when I say you can NEVER have it always. As several have already said physics beats you every time.