Hello
I'm currently running a large dungeon from 2nd ed (The Gates of Firestorm Peak) and I'm converting it to 5e. It's been going well so far (it's a good adventure, with only a few small errors) and in general converting from 2nd ed to 5e is not very difficult, although there is one problem – cannon fodder. Because of bound accuracy, cannon fodder is more dangerous in 5e – even a lowly goblin has +4 to hit, while in 2nd ed they would have the equivalent of +1 or even +0 to hit.
The party has passed a major milestone, and I am getting the next segment ready. There is one big battle happening soon-ish, and there is even a big map printed for it as part of the adventure (imagine a long 20 foot wide corridor with a few obstacles and *lot* of side passages). And well... it's 95% cannon fodder, and I'm not quite sure how to run this properly in 5e.
The party members are all level 6 and consist of a paladin (ancient), cleric (knowledge), warlock (tome/old ones) and monk (fist), along with 2 semi-useful NPCs
The foes: one HUNDRED gibberlings. The gibberlings are basically demented angry humanoid, think the tasmanian devil from loony tunes, with the fighting power of a goblin. Individually, they are very weak, but there are so many of them. There are a few brood gibberling (tougher gibberlings that can spit brain slugs at people) but 95% of them are the "regular" kind.