This blog chronicles a campaign that's basically the early parts of The Enemy Within run with modified D&D rules (I think 5E, but can't be sure):
The Dark Beneath
(They have some house rules posted
here.)
This version notably beefs up the combat encounters - lots more and tougher monsters - which I suspect is an artifact of using D&D rules.
At the other end of the scale, there's
Small But Vicious Dog, a hack of B/X D&D to fit with low-level WFRP. It would probably not be impossible to update its concepts to 5E D&D, but it might be quite a bit of work.