Solutions for Selling Tickets without a Venue

Is there a good way, or a least time consuming and annoying way to sell tickets for a show in a venue that has not been confirmed?

We have a show coming up that will be in an off-site location with a seating configuration created specifically for the show. However, we are still in the process of confirming a venue. It's possible that the existing configuration will not fit in the final location. We may lose seats in some areas, add them in another, and likely won't be able to confirm the seating arrangement until October. BUT we'd really like to be selling tickets soon and get our subs set up so they can see their dates.

When ordering, patrons should be able to choose their date and section. Multiple prices may be available in a section.

Our ideas so far include:

  1. Selling seats as General Admission and exchanging patrons to real seats later
  2. Building the venue with the map we have and blocking off large areas that we're not sure about and adding them back in if they are available. Downside: we can't add seats in another location.
  3. Selling a fixed one show subscription that can be seated later (Is this even possible in Tessitura? I've done this in PatronManager)

Your solutions and recommendations are greatly appreciated!