The slightly warmer (i.e. above freezing) weather we've had the past two days gave Lisa an opportunity to try and fit the replacement hose into the radiator system on the Astro. It fits, but not the way she would like it to fit. We simply can't find the shaped hose that we need for that location, and even the GM service manuals don't give a part number for that particular hose. We may need to go to a dealership with the service manual, point at the diagram, and say, "We want that hose #201 in that drawing, whatever it is." However, the hose she got does seem to do the trick for now. We went to O'Reilly and bought more coolant to deal with what leaked out during the repairs, and Lisa started the minivan and ran it sitting on blocks for a while. The temperature came up, but not too high, and heat came from both the front and rear heaters, and it did not start leaking, fizzing, and steaming. Tomorrow she'll put the "doghouse" cover back on and we'll drive it around Fernley a little bit to test it out.
Of course O'Reilly would send me about the time we got home a $5 off coupon that would have been ideal for applying to the $17 jug of coolant we bought.
It's a great relief that it appears that the coolant leak was a split in a rubber hose and not something more serious.