I just returned from the same itinerary on Saturday, July 13th. I'm not sure if you are aware, but our itinerary was changed at the last minute. They removed the 2 ports on Greenland and substituted Nuuk instead due to too much ice in the ports. They also removed one port in Iceland so we ended up with an extra at sea day. We did see icebergs, and there was heavy fog and high winds. I would recommending bringing warm layers, gloves, hat, and either hiking boots or shoes. Most dressed very casually on the ship except those I saw getting special family portraits done. Let me know if anyone has questions and I'll be happy to reply back. Enjoy your trip!