Just recently unlocked this and tested it out for a few days.
Turns out that the Survivalist trait does more than it says it does. There appears to be several effects:
1) Using either the Tarp or Waterfall Showers will provide a Rustic Comfort moodlet for 6 hours. This stacks with any of the log/stump seats which provide it until unused instead.
2) Sitting on any log, stump or Gordian seat, provided no other action is in effect, will periodically recover energy.
3) Sleeping in the uncomfortable Gordian bed will recover energy faster than normal.
4) Waking up outdoors, either by tent or bed, provides a 6-hour Primitive Awakening moodlet.
5) Eating Veggie Dogs gives a 6 hour Simple Satisfaction moodlet.
Some of your sims may thank me later for this info.