How do you understand the phrase 'a couple of something'? Do you immediately associate it with 'two things', 'several' or maybe both?
I know context makes all the difference, but I heard a native speaker argue quite strongly that the primary meaning of 'a couple of' is 'two'. He admitted, but only reluctantly, that on certain occasions it can mean 'several' e.g.
I need to find a couple of things before I leave.
Do you feel as strongly about the phrase?
I would say not "several" but "a few.
It's primary meaning is two, but I'd say as many as four could be used in the type of phrase you quote. But not "several."
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.