I love my Nemo Sonic - had the same debate and was going between the WM Sequoia and the Nemo Sonic. Got a good deal on the Sonic and I love the bag. I can't remotely do mummy style.
This. Doesn't matter how much ambition or drive you have or how hard you are going to hunt.
edit - Also don't expect any landowners to be open to letting out-of-staters hunt or even residents hunt. I've spent a lot of time out that way and there are far better places to spend time looking for deer.
I was looking long and hard at the Sequoia, but ended up finding a super good deal on the Nemo Sonic 0. If I was going WM and was a side sleeper or needed some extra space from the mummy style, I'd definitely go Sequoia.
Have you been to Montana before? Or are you just moving on a whim? Montana is extremely diverse and you would need to know the specific area to determine heavily forested vs glassable country. I've used my 12s everywhere and havent found a need for 15s
I've been looking at the Nemo Sonic 15, Nemo Sonic 0, and Nemo Disco 15, so I am interested in other's opinions on the Riff as well. Been leaning toward the Nemo Sonic 15...