First off, if you can wait and let them know Monday, the merged list should be done tomorrow. That should answer the question of fences, Also, every day is that much more seniority lost (which is everything) I'd say take the earlier date. Mesaba is flying flights CHO-LGA so that would give you higher priority for getting on those and once the merged list is done (before your class date) you would likely be able to bid to any Saab base you could hold (see seniority comment) without a seat lock.