Or are they hidden in the raw data FIT files that the ANT software can decode into CSV and then to a spreadsheet?
Yes, you can export the daily data in the FIT file format. You can export it on the Daily Summary page - see the cogwheel symbol up right, and select the option Export Original.

trux, THANK YOU... that was exactly what I needed. I was able to convert the .FIT file to .CSV and get the data I needed.
I have one more hurdle. Right now I can download detailed Stress numbers for each day (in the wellness files). How can I download it for ALL days? I've already done the "Data Management > Export your data" option from Garmin Connect web. I've scoured all the files and I can't seem to find the Stress data. Any suggestions? I've opened a support case with Garmin but haven't heard back yet.
I really appreciate your help... I feel like I'm very close to what I need!