I'd interpret that as "2 days", with the implicit assumption that you can come back after 2 days and we'll still have them. A couple of km shouldn't really mean

I'd interpret that as "2 days", with the implicit assumption that you can come back after 2 days and we'll still have them. A couple of km shouldn't really mean more than 3km, but obviously we don't expect anyone to go out and measure them. I'd allow that "a couple" could mean "2 that I'm certain about, but possibly 3 or maybe even 4".