I'm not a fan of this storyline either. However, bearing in mind Tyrone is worried it could be Hope's last Christmas, he wants to make her dreams come true.
Since charities for terminally ill children exist for this very reason, it must be something that many of their parents want to do. I just had a look at the Make a Wish Foundation site and it mentions a couple of kids going to Lapland:
https://www.make-a-wish.org.uk/