It happened on a few occasions. One was summer definitely. Generally, in the quieter seasons I could find a reasonably priced HI and would stay there instead so I suspect there would be a spring/summer/early autumn bias.

If you are struggling, I would take it. As I said it was somewhere I would stay if I had exhausted other possibilities. If you do get a noisy room, you can always asked to be moved if staying more than one night - for one night, it was never worth the hassle.