A: You will almost always find you have characters who conflict directly on one date or another. The trick is to get the person home first who requires the unpatched year, then flip it and patch it for the second person.
OR… Patch it for the first person, get them home, and then flip it back to the True History side, and lose the patch, since you no longer need it. It’s not required for you to maintain ALL characters’ win conditions at once.
The only problem is that, as I said, you’ll find MANY of your characters have conflicts like this, and you may line them up in the order you have to get them home… and find that it’s circular. In those cases there isn’t a way: if there isn’t one character whose conditions can clearly be satisfied first, clearing up a conflict for another, which then clears up conflict for the next and so on.
It is definitely possible to get them home if this is your only conflict. Of course, the deck may not play nice with you and give you the patches you need in the order you need them. It’s a solitaire game, and it’s based on a randomized deck of cards, and there has to be a real and fairly frequent chance you’ll fail, or there isn’t much challenge.