Since my gear list critics were so awesome, I thought I'd drop another question. Several people mentioned my choice of 20* bag leaving March 1st next year is way too cold. Well, not only is the bag over $300, its 1lb 11oz. I'm here to ask if you know of either a light, cheaper alternative, or if just throwing in a sea to summit mummy liner would add enough to work, then once the temps warm up just send it home? Or even a light cheaper alternative, with a bag liner.