Nice simple solution but safety's sake, I'd keep a close eye on it. That clamp was not designed for quick-release, and high frequency folding/unfolding of multi-modal commuting could fatigue the steel and/or welds around the clamp. I took a look at my Dahon QR handlebar clamp (which is needed to fold) and it has a robust hinge & pin design.

Another option might be a handlebar stem extension (eg, Aber Halo Stem) but with QR, and then a low riser handlebar to offset that added height so bars don't drag on the ground folded, or need longer cabling.