It turns out I made a major error in not getting food and water lined up the night before: in trying to do this in the town right before the climb began, I ended up losing a full hour and a half since it turned out the town was off the route and most of its shops had closed.
This time loss proved critical, as it meant I reached the top of the pass just as the sun was setting. This meant that the ride down the mountain was done in semi-darkness, with the help of the headlight (which I'd gotten working again). After all the descents with their hairpin turns (and thoughtfully-provided cattleguards that left me riding the brakes the whole way down) the headlight charge ran out completely about five miles out of the town I'd hoped to get a motel room in.
The thing to keep in mind about this five mile walk was that it was in TOTAL darkness: no headlight, no flashlight, no street lights, no lights from human habitation (because there wasn't any), no moon, and no cars. Honestly, although having to continually scan the ground for cattleguards was a drag, I do have to say that walk was one of the coolest parts of the trip so far. If nothing else, the stars had never seemed brighter.
Unfortunately, though, the town was a total bust: the motel apparently doesn't take anyone who hasn't scheduled their stay earlier in the day at some cafe adjoining the motel, and the b&b was full. Again this was critical, as I then had no means of recharging my headlight, and of course all the town's shops were closed, so getting an inexpensive flashlight wasn't an option. Oh yeah, and to boot, the town apparently turns off its streetlights at night.
So in other words, I had to set up my tent, and manipulate the combination lock for the bike, in almost total darkness.
So, a mixed bag.