Back in the "dark" ages, Kodak Film cans (grey with black tops, or black with grey or black tops) were considered light tight. (the current ones are clear to make it easier to inspect at airports I guess).
I have had a lab send me back a film that they detected a tear and did not want to process in a grey Kodak can, and was able to get another lab with a dip and dunk machine to process it successfully several weeks later.
If you keep one of the older cans handy, you can stash the film in at any time. While I have not done any tests, I would guess that the Agfa and the Foma/Arista.ultra all black cans are probaly also light tight.