It turned out that 6:30pm and onwards was the perfect time to get on every ride at the Magic Kingdom with no lines. So much so that, as I walked through long empty winding corridors, that usually hold lines of people, I sometimes wondered if I was going to get mugged!
The reason it's a great time to get on the rides is because people line up an hour or more in advance to see the 2 parades and the fireworks, so if they're THERE, that leaves very few people on the rides! The first night I missed the fireworks but I caught a few from the top of a Splash Mountain. That was cool! I, and several cars of strangers, cheered each time fireworks burst over our heads as we we zipped up and down the tracks.
Speaking of parades, I finally caught one. I'd never seen a Disney parade before, but I decided to watch the 11pm Spectro Magic parade. It's AWESOME! I am now in love with the bizarre, and kind of creepy, clowns at the beginning of the parade. Particularly the ones spinning around on what look like giant lit up Christmas Ornament balls. SO cool!