A quick way to see the Delta seat map is this web site:

http://www.benedelman.org/travel/dlseats/

Assuming you are on DL 397, there are 4 mediallian exit row seats available (I think you can select these at some point near depature ... maybe others can help).

I would check this web site on Friday and especially Saturday morning. I bet some seats open up with mis connections and/or cancelled flights.

There are a bunch of rows reserved for airport control. One strategy is to change your seat assignments to unassigned. The people working the flight go to this list first (once you have checked in) to take people off this list into these seats (works better if you are both in one record). They often do this before showing up at the gate (this is why they are often "gone" when people first talk with the agent). The downside of this strategy is if the flight ends up being oversold (without enough volunteers) you could be bumped. I have done this several times with my kids and we end up together. Right now there are a lot of F seats available and they are still selling 6 in Y. So, I doubt this will be a involuntary DBC siutation

Good luck!