Hey, there are a couple of things I've noticed, although I'm not sure whether they've been discussed yet:
1. It's possible Joey & Meghan win TAR. According to a post on tumblr I've read, Joey and Meghan said they would buy a house with any prize money they get should they win in an interview. Coincidentally, Meghan moved house recently as she documents in some of her recent YT videos,
2. The Titanic Quarter was recently built in Belfast to commemorate those who died aboard the ship and has become a huge tourist attraction. The building is seen in the pre-roll before each episode begins when each team is being visually re-introduced. It's highly likely that there are challenges that take place here as there are ports, clubs, museums, arenas and a train station all within a 5 minute walk.
3. It is said that the final legs are going to be Scotland -> Northern Ireland / Northern Ireland -> Washington D.C.. It takes roughly an hour and a half by ferry to get from Scotland to Northern Ireland, and only 45 minutes by plane (this is all from experience). In my opinion, I think Switzerland -> Germany will be an elimination round, and Germany -> Scotland NEL as it would take so little time to get from Scotland to Northern Ireland, and that the last two episodes are being aired as back-to-backs. Which means there will be four teams up until the last two episodes.
4. Apparently, Joey Graceffa also commented on his twitter that he had visited Scotland meaning that both him and Meghan will survive for at least another 2 episodes.
If you can help me find proof for any of this (as I can't find a shred of any interviews or twitter comments!) I'm sure everyone would be very grateful!