I'd like for the dungeons to also be explorable in the overworld map

[TheMightyMollusk]

Average clear time is 20~ minutes.
You have a 90 minute timer to start.
After clearing, just hit Return to go back to the entrance and then you have over an hour to make your screenshots.

Stick around after final loot rolls some time. It gives you a shorter timer (I believe 5-10 minutes) before ending the instance.