you could try a threadless steer tube extender: http://www.amazon.com/Dimension-Stee.../dp/B000GASQ00

cut the steer tube 1.5 inches like you described, keep the same stem, and add the extender to bring the height back up to your current position. Then when you want to put it in the case, just take off the extender.

I highly doubt you're going to find a higher stem, so this seems like the easiest option