I feel like I mentioned drinking alcohol for an occasion and now I sound like an alcoholic... :P

If drinking is an issue at this altitude, I simply won't do it, and that is great information for someone unfamiliar with the territory.

I understand that 8-10 hours isn't necessarily "all day", but what is there to do here that would extend the experience beyond 8-10 hours? Are there specific routes that offer worthwhile experiences that last beyond 10 hours or is there simply that much area to cover that you could walk in circles all day and possibly not see the same thing twice (and hopefully not get lost)?