Appliance Pros suggested that a failed defrost timer might be the problem. We put the frozen food in the small kitchen freezer and ordered a new timer. With standard shipping we received it in two days. It took about 15 minutes to install and that includes hunting down a nut driver of the correct size. Four hours later and it was running at minus 5.
Suggestion: We did not think about the amount of water resulting from the melting ice. Once the pan was full it was difficult to pull the freezer out from the wall without spilling water. (The timer is on the back.) If I were to do it over, I would pull the freezer out from the wall and unto a plastic sheet. Or better yet, haul it out to the patio while the ice is still ice. After the part arrives just tip the freezer forward a little and let the water spill out.