When is the latest the heroes can flee a dungeon? More specifically, can the party defeat the third-level leader, then glyph out saying, "We are fleeing the dungeon?" I see nothing against it in the updated FAQ, rules, forum, etc. If you say it can't be done in that circumstance, would it matter if there were other beasties remaining in the dungeon (so the heroes can reasonably claim that things are too grim, per the Fleeing a Dungeon section on page 18 of the rules).
I think the question can be answered without the following information, but I'll provide it anyway.
Our party is handling the OL pretty well in dungeons; however, he has been extraordinarily lucky in his resolving of seiges (razing cities on three of four attempts) and is now handing us our butts on topside. We cannot afford to lose another city.
We just descended into the dungeon at Misty Plains and he has two seige tokens on Forge. If we conquer this dungeon, he will have four seige tokens on Forge by the time we get to Red Echo River (we have the Staff of the Wild). Next turn, he will get one crack at razing Forge (he has seige engines) before we enter the city to attack the lieutenant. Given his luck, Forge will be a smoking ruin by the time we get there.
I realize this is a munchkin move (no offense to munchkins or munchkin players), but fleeing a dungeon to teleport effectively back to Tamalir will allow us: to clean up a dungeon and eliminate the evil OL the possibility of razing a fourth city.
Also, we are 45 points into silver level.