I'd have trouble keeping up with y'uns on my 24", though I've gone a marathon distance. Remember, there's no coasting on a uni and no speed gain on a downhill. I'll look into borrowing a larger one for the next FOC.
I've been meaning to try out bigger wheels, anyway. They make 26", 28" and 30" unicycles. I'm guessing that the local experience base with using a unicycle for a 16-mile-each-way commute is, um, not robust, and seek to remedy that.