Unless someone has recently flown this route and had comments it is something
that is not checked and published. The best method is to for you to find out for yourself.
Since you do have the Delta TravelNet keep looking daily and make a log of what
you find to get your own level of comfort for potential space availability.
See how your pass class fits on each of the days and flights paying attention as to
who is filling those seats in the front cabin and how many empty coach seats are
left as a buffer if any.

To get a better summary use the revenue site Delta.com and take a look at the
seat mask to see the seats left for selection in both cabins and monitor that.
Know as much to know about your flight.

As a hint have portable internet with Wi-Fi on the day of the flight logon to the
TravelNet site and the ASL and watch how the standbys are cleared. You are
there and almost right beside the Gate Agent clearing the standbys.