I usually have a 70-200 f2.8 IS les with a 1.4 extender on when I am in the woods.  I leave the lens cover off and keep a lens hood on.  With a couple of thousand dollars around my neck I am just real careful with it and aware of my surroundings.  Turkey hunting was the first time I had it in the woods this year while hunting.  I would tuck the lens hood in between my vest  and body and it kept it fairly secure.  I have the grocery produce bags in case it needs a rain coat.
I would say that if you think it would be a huge mistake carrying this equipment around it probably is for your situation.