I voted 'continue to try to sign him', although it depends on what the offer is. We only gave up a first round pick to get him so if we can actually get more than that I would take it.
I'd be curious to see what he's worth. He'll be a free agent next year so any trade would likely be a rental. Personally I'm not confident we'd get more than a first round pick. Miller was kind of the perfect storm where he was the best goalie available, had a good track record of success (regular season and Olympic, not playoff though), and the Blues we're elite everywhere but in net so it's worth the picks. Schneider doesn't have the track record.