Seems like icebergs are getting later each year. Late Jun thru early Jul will give you the best shot with the largest bergs. Not much, if any in May. Anywhere along the north coast to view. But Twillingate would be a nice destination. Skip the 4 season tent and bring a good bag. Rain may (will) be an issue, in that you won't escape it, and it'll be cold. Bring some bug repellent, but the last number of summers Ive never had to use any.