A week is probably safe. In order to put the kibosh on it prior to 5/11/2020, the FDA would, at a minimum, have to issue formal "guidance" directing it only be sold to registered tobacco products manufacturers. This would take some time, and I think we'd have at least 30 days notice.Yes, it would be unwise to assume nic will be available to us as part of the post-May deadline. I know that. In fact, it may be unwise to think it will be available to us next week.
Of course that's been the same situation since 8/8/16, which is why I set (and achieved) the goal of being done before then for myself. I was never a boy scout, but I do like their motto.