RE: Ethical/Legality?
I can speak to MN law.
Thing is.. you can call up the warden and have him explain the situation to the landowner who is refusing you permission. However, the warden, much like yourself, has NO RIGHT WHATSOEVER to enter that land without permission. I am sure that nine times out of ten the landowner listens when the warden gets called in, but if a landowner has already told you no, he can do the same to the warden.
However, if the land is not posted, get in there and grab your deer. The sucky thing about our laws here is that if you absolutely, 100% want to be civil and nice about it and knock on the landowners door first and ask permission, and he says no, then says no to the warden, you are SOL. If however you trespass (providing there is no signage and you havent been told to leave) you will get your animal.
This, IMO is stupid.