I put together a sample python program that should dump out the devices in your account that are missing where_names.
The code is available at https://www.liquidreality.org/files/nest/find-missing-where.tar.gz
It requires a working python and virtualenv. Once you download it and uncompress it cd into the find-missing-where directory. You then need to create a conf.yaml file that has your product_id and product_secret in it (product_id = client_id and product_secret = client_secret from your home assistant config fill).
Once you create the conf.yaml just run ./run-test. This will create a virtualenv to run the code in and execute the script. The first time you run it the script will provide a URL to go to get to get a in and enter it into the script (similar to the first time you added nest integration to home assistance). It will then go through and find all devices associated with your nest account that don’t have a valid where_name.
Please let me know if you have any questions or problems.