I should premise by saying I have never been to WDW during a peak time like easter week - However, I was there this Past Pres week when MK was open until 11PM or midnight most nights and nighttime EMH was wed from Midnight-3PM. So my advice is, go to MK on a non EMH night - late. DD and I went there twice after 10PM on Non EMH nights and many rides were walk on's. The night of the EMH, some of the crowds did not thin out until about 1:30. OH, and another little tidbit. Don't always belive the wait times posted. If you've been there before, you can usually guess whether a wait time is somewhat accurate or not, but 2 times that I can think of they were very wrong (overstated). One was EMH at MK for BTMR. When we first got there, 30 minute posted wait time. We could see the line from the entrance, so we did not venture in. Instead we rode SpM with no wait. When we exited SpM. BTMR still had 30 minute wiat, but we couldn't see anyone. So we ventured up and sure enough, it was a walk on. On another evening, at Epcot, TT showed 45 minute stand by and 20 Minute for single rider. It was about 4 minutes of 9PM. We walked in and there was no one there. No wait at all. So especially late at night, but sure to at least check it out!
Good luck.
Good luck.