So it can be awkward fitting a sleeping bag in it's compression sack inside a backpack, but you don't need to use the compression sack. Here is what I do: put a trash compactor bag in my backpack then jam in the sleeping bag. At this point the sleeping bag takes up the whole backpack. Next I add my clothes jamming down on my sleeping bag. As I pack the rest of my equipment I compact my sleeping bag. In the end I have more room in my backpack because the sleeping is free to fill up unused nooks and crannies. I think you'll get a much better packing with a big bag like that Buffalo.