When schedules that are out of your control change at someone else's initiative, that can be hard to adapt to. On the other hand, I sense that you are attaching before you have any interaction with this dog. Or at least I haven't read that you have interacted with her. If that's the case, I'd see if I could back it up a bit on the emotional attachment to the image of this dog. ie, keep it real. It can be hard for me to walk away once I do meet a dog (good match, not so fine, or something else). It seems like you've already built this in to the "picture" and that may cause you to be far from pragmatic when you "see" the "real thing."