So I just saw the Olympe Nimbus in Anthracite today IRL and I am in LOVE. But, I wish they made a size between the PM and GM....what's a girl to do??? I am 5'7" and 118 lbs. Which bag do you suggest and why? I am really on the fence on the size because the GM is fantastic for all day every day, but the PM can transition into the evening.....sigh, please help, Thanks!