Dipper and Mabel vs The Future

Eh, I decided to post my thoughts on the upcoming Gravity Falls episode
First of all, WHY MUST THEY MAKE US WAIT THREE WEEKS FOR IT? #thepain 
Ok, ok, sorry, gotta calm down
So, what I think is gonna happen is that Dipper and Mabel are (obviously) going to go into the future. Here are what I think are the possibilities of what they might see
1) The world has been taken over by Bill and is in chaos (cuz, ya know, all his demon buddies are messing shit up) Another thing is that it could have been their fault, like they made a mistake that lead to Bill taking over the world
2) Either Dipper, or Mabel, or Ford, or Stan, or someone is dead (although that would suck, I would like to see their reactions to something like that. i.e. Dipper sees a world where Mabel is dead and freaks out and becomes protective/even more pissed off at Bill)
3) OR (this is what I think the most) Dipper and Mabel are going to see themselves in the future, but they're relationship is all broken and damaged like Ford and Stan's. Ever since the end of A Tale of Two Stans when Mabel made me realize how similar she and Dipper are to Stan and Ford, I keep thinking that 'what if Dipper and Mabel have like a fallout or something'? 
Idk, these are my thoughts. Share your ideas with me in the comments!