This is a great question/goal, and I have a partial answer for you
The Gates of Firestorm Peak
Spoilers ahead!
This adventure is a "kilodungeon" - about 125 rooms. This is a complex where the door only opens ever 27 years. The gate, and adjacent complex, are controlled by a duergar clan who are mining a special material (transparent iron basically). The opening of the gate is foretold by a comet.
The dwarven complex is only the first part of the adventure - the dwarves have been taken over by an evil wizard, and once his peon king is killed/dealt with, the rest of the clan may be willing to assist the PCs in getting rid of the evil wizard, who is deeper in the mountain with all sorts of mutated monsters - this is the adventure that introduced the concept of the Far Realms, and it's very well done.
I don't think this is a perfect match for what you are looking for, but you could still use it and ignore some of the details (the gate opening once every 27 years, the evil wizard, the far realm stuff)
as far as "dungeon crawl slog" this has the potential for it, but it is helped a LOT by the 125 rooms not being the same - in fact there are several "zones" with different foes, flavor/vibe etc. The Duergar compound is just one of them (depending on how you look at it, it could be divided in 5 "zones").
I've run the adventure twice in 5e and would do it again!