tv, a couple of thoughts: Cycle Oregon top dawg Jerry Norquist lives in Sisters (just east of the pass) & would be a good guy to palaver with. It may be something the Sisters bicyclists do already... Finding someone at ODOT (since it's their road) would be a good idea, so i'd start with to Sheila Lyons, the state bike/ped coordinator, once you know what it is you're asking for.
I don't think it's in any way *illegal* to use it on a bike before it's officially opened to traffic...?
great idea, run with it! i love the concept of a "floating" event that has no time certain...