All survey results are anonymous. Although you can see the individual who completed the survey under Reports, their responses are not visible...only the roll up of responses on the Training Material Statistics tab who's how many answered what to each question, etc.

We are hoping to use a survey as a “temperature check” midway through a course. Is this something that is possible?

Yews of course...a survey is just another leaning object. You have the choice to create a unique saver directly in the course or if you think you will reuse the survey, you can create directly in the CLOR and choose whether the survey data will be tracked as unique for each course using the “local tracking” option or if when the user answers the survey once, they are done with that object wherever is is used, called the “Shared tracking” option.

https://help.docebo.com/hc/en-us/articles/360020128919-Creating-and-managing-course-surveys#h_01HFS5SVBGNDHBKE88SNWZSN0J