You will have to think about water freezing, if your Elk hunting is in country that I am familiar with. Do not fill the bottles to the top- freezing can crack the plastic container. Leave about an inch at top for expansion. Not so much a problem when inside your pack going in, but a big problem while in camp overnight. Wide mouth bottles work better when it freezes. Once water in my Platypus bottle froze and it took two days to shake out all the ice! Often the lid will freeze tight. You then have to use your hands to warm it enough to open. One good thing about metal bottles is that you can heat the container to melt the ice. I would have at least one metal bottle that you can put on a stove. Once you get some water heated, you can stick the plastic bottles in the hot water to thaw. One idea is to make a hole in the ground for water bottle overnight storage and cover with leaves, etc. I would not keep water bottles inside the tent - if they leak you are in for trouble. One small bottle inside the tent at night for sips is fine, but not a bunch of them.