Ask HN: How large would a current ChatGPT snapshot be? Is OpenAI keeping any?

ChatGPT is a service and as such changes and improves over time. Computing power is also expected to improve continuously. At some future point, hobbyists might want to run a retro version to know what kind of knowledge people had access to "back in 2023". OpenAI might also agree to open source past versions. But if they did, can future hobbyists expect to be able to run such a snapshot? how large would a current ChatGPT snapshot be? Could future hobbyists run one, if OpenAI agreed to open source past snapshots? Are such snapshots being taken and retained?