I appreciate all the good advice....
Am leaning toward #1, leaving at noon (packing truck in morning), and driving to Rawlins, WY (not sure I could make Green River/Rock Springs. There's a MUCH nicer option for decent hotel in Green River for not that much more than an slightly worrisome place in Rawlins
).
Day number two, I'm intrigued by a couple of the mom-and-pop motels listed at Glenns Ferry, Idaho as a second-night stay. (Just wish that the route didn't bypass the most northern Salt Lake City In-N-Out Burger
)
I'd probably spend a third night somewhere around Ellensburg WA and then have just 2-3 hours for the final morning.
A little leisurely, I know, but the days in which I would routinely drive 700 miles in a day and think little of it are long past....