I've only ever sailed to Canaries on QE2 but we had quite a calm trip. Only once did we have any bad weather as we left Gran Canaria but the ship made light work of it. I've crossed the Bay of Biscay 6 times now and not had a difficult crossing yet!!! I hope this is of help to you.
Done this cruise 5 times on various P&O ships and never had a proble.