Big THANKS! Wife just called and said that she told them about the overheating and to check the fluid level. They said that the fluid level was fine and they can find nothing wrong. They agreed that it probably overheated. She had them run a diagnostic on it and no problems found.
I really appreciate the advice here and offers of help. Not saying that they would've taken advantage of a lady in trouble, but the wife was so relieved to have some good information to bring to the discussion.
Told her that once she gets home, we'll take a look at the cooler and get the seals checked. Told her to enjoy the rest of her trip and keep an eye on things.
Thanks again!