...That's a very hard standard. While I think it's possible at the room key level, the overall dungeon will usually need at least a skim if you want something that has connectivity or even complex traps and puzzles. What I personally aim for (and again I tend to be a maximalist in adventure design) is keys that can generally be read and used straight off the page, but larger dungeons (over 10 rooms) that require a small amount of prep - say 10 minutes per hour of play. So a 10 key jewelbox dungeon is something one could just read as you run it, but might do better with a quick read over. A 50 key, five level dungeon will be more involved and the referee might need to read through it once and write down some notes. Of course a 50 room dungeon with that level of detail is also likely to last 10 or more sessions, and I've even seen small dense jewelboxes take 2 to 5. Arden Vul is like this on the grandest imaginable scale.
Basically the more engagement with the adventure one wants, the more details, interactive elements, and connections between keys it has ... the more engagement the referee needs to have with it during prep time. I don't think it works any other way. I'm not a big improvisational referee though - I suspect some of those folks can wing a complex adventure from a couple of notes.