Well, doing it KQV/6 style would be interesting from a novelty and originality standpoint. Plus you could essentially make it your own game. I remember someone else that wanted to do that, but it never went anywhere.
If you were going to go that route though, I'd suggest trying to make it a Quest for Glory type interface. Maybe include random encounters, and a more advanced leveling system, mimicing QFG. Like you can't just climb into a place, unless you build up enough climbing skill for example.
You could also maybe add "class choices" that could open up alternate puzzle solutions, heh heh,

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However, you'd be creating a game that's kind of like possibly having seven QFG1/4 type worlds in one game. You'd need a at least 16-20 screens for each world's outdoor areas. So roughly 112-140 screens to explore around. That's not counting indoor areas. You could reduce that number a bit by using overworld map like in QFG3/5, as well as cloning and reusing random trees/rocks to create screens like in QFG.
Absolutely huge for a KQ game let alone adventure games in general.