Obviously there are risks but, if you're prepared to accept those, it's an experience of a lifetime.
i might join him in Goose Bay or Reykjavik
Joining him in Reykjavik would mean missing out on the best part of the flight.
Join him at Goose and route via Greenland.
I guarantee the memories of flying low level over the ice-cap and close-up views of stunningly beautiful icebergs floating around the coast will stay with you for the rest of your life.
Go for it!
It's a rare opportunity and you'll regret it if you don't.
FL
(Edit)
I'd recommend joining him before Goose so that you see more of Canada from the air.
If free time is a factor, you could always fly home schedule from Reykjavik. There's nothing but water between Iceland and Scotland, and you'll have seen lots of that.
