I will be going to Colorado in September.i have to get a good bit of gear for my trip so I'm not trying to remortgage my house for the trip.i have seen some talk about these packs.we will be setting up a base camp but me and another guy may go out on our own for a day or so.im just trying to figure out what size pack would be best to get.i hate to go to big that I wouldn't be able to use it just going for the day and to small I wouldn't have enough room for what I need for a day or so away from camp.sure these questions have been talked about.any info will be appreciated.thank you