Overnight in Elora - where to eat?
You will be right between two fairly good high end places (if that is what you're looking for). The Millcroft Inn near Alton is very good, with a good wine list. South of Kitchener, Langdon Hall has both a high end restaurant as well as a good pub menu (burger with a slice of foie gras).
Closer to town, I've heard good things about the Elora Mill, which has both a high end and bistro menu, but haven't tried it yet. If nothing else, it's scenic enough to stop for a beverage.