Sometimes it is nice to see that planning ahead really does work. Several years ago I had to repair a leak at the water meter and at the same time I replaced the old hard-to-turn faucet handle with a gate valve in the nearly household water shutoff vault. This morning I pulled the lid and remembered all of that previous work and expense as I reached in and easily moved the gate valve to "off."
I then disconnected the fridge water tubing, topped the brass pipe with the new brass cap and it worked perfectly. Water back on, no leak. I taped the tubing to the back of the fridge, and used a hairdryer to melt the ice. I'll reserve the top shelf for ice trays for filling the still-functional ice dispenser.
Now to get to the de-clutter work I actually had in mind for the weekend.