Re: 45-70 or 300 Weatherby
Take both. If you know the turf well you can pick long or short (300WBM or 45/70). But if the country is new to you take both. Can switch out to the best rig for the situation. I've hunted places in Idaho where out on top the range is about unlimited but the draws are like jungles (or maybe rainforests).
Take both if you have no problem doing that.