I can't believe this is apparently a thing, but ok, if it's really devolved as much as the reports seem to be saying, then I would say moving Miller makes the most sense, regardless of EP40's flaws. Considering his age and history of much better performance not so long ago, and his recent enough worse performance, VAN would take an L on trading him, no matter what.
I agree with the idea that Miller to NYR in a deal involving Zibanejad makes a lot of sense. NYR's locker room is already broken, very obviously, so might as well try something. Miller's contract is slightly better, so some kind of add from NYR's side should be expected, but not like a 1st or top prospect or anything.
Or, I wonder if something like this could make sense, when Hronek gets back or gets closer to returning:
Miller + Hronek (no NTC) for Zibanejad + Schneider
NYR has the cap space for this with Trouba traded for minimal salary in return and presumably wants to stay in contention, Hronek could thrive in a 2nd pairing role behind Fox, and VAN gets about 5M in cap space to make adjustments to the roster, plus adds a nice younger piece in Schneider at a position of need, at the cost of a player who has performed excellently with Hughes, but hasn't been extremely consistent, nor does Hughes need him to perform at his best anyway.
No idea if this really makes sense or not, I imagine NYR fans like Schneider too much to do this, and the cap space exchange is probably not realistic, but it's an interesting thought...