After dinner, Lisa put the "doghouse" cover back on the minivan and poured more coolant into the radiator, and we set out to drive around Fernley. The first trip out led to a quick return to base, as we got little heat from the van's heater and a higher-than-desired temperature gauge reading. After letting things cool back down, Lisa checked, and sure enough, the coolant was low; air bubbles in the system. She put more coolant in and we tried again.
There's a subdivision in Fernley where they really go all-out with their Christmas light decorations. We drove down there (watching the temperature gauge), parked, and walked around the neighborhood. If you'd like to see the rest of the light show, see my Fernley Christmas album on Flickr.
After checking out the lights, I decided to pop up onto the freeway to make sure the van can handle high acceleration. To our annoyance, the temperature shot up and fluctuated erratically, which suggests that it's still not full due to air pockets, so we went back home and if it's still low when it cools down again, we'll put in more coolant.
There are no leaks or clouds of steam, so we think the main problem is dealt with for now, and I'm grateful to Lisa for going all of the dirty work under the minivan. I do need to get the van in to have a complete coolant and oil change, however, when I can do so. I hope that I'll have a chance next week.