Perhaps the vampire gang can fast forward (because in their timeline it's lagging compared to everyone else even if they are in oblivion or elsewhere, fast forwarding is necessary I think) and run into her. Then they'll head up to the college to seek knowledge and protection. Dabiene, as one of the "head guard staff" there will walk down with Soldin since he was technically sent by the Dawnguard to keep up security status up and gain knowledge on how to deal with "this whole insane mess".
I don' know. Is Chief still around?