Really depends if you were already planning on spending at park day at DHS. In my opinion (and I'm sure it won't be popular), if you'll already using a day at HS then I don't see a problem with staying at HS for dinner. With H&V (and try to show up a bit early), I see it very possible to be in MK before 7pm when all the real party festivities begin. From 4-7, in my opinion, isn't what I'm paying for when I buy a
MVMCP ticket, I'm paying for the exclusive parades, fireworks, and character greetings. Mind you, if you arrive late, I'd advise staying through the end of the party (midnight) to get the most bang for your buck.