Call the Sports Authority. They might just be able to do it. Wilderness Sports would be where I would first check for split rentals. I am pretty sure if they don't rent splits someone else does in Summit.
So I leave for Washington March 8th. It is totally worth bringing your split. If the snows there. I'll have a better idea come February if you really want to bring it or not. I'll make time to get out that first weekend or during that week with you if it's a go. I'll be in Gold Bar from March 8th-18th. My riding time is the 9th through the 17th. Looking forward to some PNW goodness.