How long before Standby/Deep sleep mode is activated?
You can list some power management settings with pmset -g (get). The default standbydelay was 4200 seconds (70 minutes) on my MacBook Air.

$ pmset -g
Active Profiles:
Battery Power       -1
AC Power        -1*
Currently in use:
 standbydelay         4200
 standby              1
 womp                 1
 halfdim              1
 hibernatefile        /var/vm/sleepimage
 darkwakes            1
 networkoversleep     0
 disksleep            10
 sleep                15
 hibernatemode        0
 ttyskeepawake        1
 displaysleep         15
 acwake               0
 lidwake              1


According to Apple Portables: About standby mode, "the standby mode activates after just over an hour of "regular" sleep".