Update: As of February 28, 2019, new Hot Network Questions will get an entry in the revisions/post history table, with type 52. You can use the API (and probably SEDE as well) to search for these events.
As indicated in an answer to the linked question, there is no such official list and it's not likely that there ever will be one.
The closest you can get is community projects regularly scraping the HNQ list. As described here, I have one which does this once every 10 minutes since August 4th this year. There's a PostgreSQL database backup of the data up to September 2nd; I will try to update it regularly in the future. The
questions table will contain the site, ID and title of the question; you can obtain other data via the API or the Data Explorer.