I don't see much reason to carry more than 3. My only concern would be during the rut, if you are going to be on stand all day, and you have "one of those days"....

Another concern for me is dropping them out of the stand. Now that I shoot a biscuit, they don't fall off the rest, but I have still knocked one or 2 out of my quiver pulling up my bow. I'd have to climb down if I only had 3 arrows.

With the exception of one deer, (5 shots...don't ask, it was a LONG time ago) I have never needed more than one arrow.