We were there on the last night, as well, and we had a delightful time. It was me (grandma), my daughter (DD, age 45), daughter's fiancee (DF, age 43) and my granddaughter (DGD, age 14). We entered the park at 4pm with just our MVMCP tickets, and we followed the plan I had laid out in order to do a couple of attractions that wouldn't be open during the party (like Jungle Cruise). We avoided the first parade, and watched the fireworks from near Dumbo. We had originally planned to try to get around to where we could see the front of the castle for that part of the display, but decided to see Mickey's Philharmagic instead. We came out of that show just before the fireworks started. When they were over, we decided to go see Philharmagic again, while the crowd dispersed from that area.
DF is in a wheelchair, and can only transfer with all of us lifting him, so we were delighted to get to ride the wheelchair boat for Jungle Cruise (as well as It's A Small World, of course). The CMs at The Haunted Mansion were SO nice! We went there at about 6:00, and it wasn't at all crowded. They even let us go into the stretching room before taking us to the exit area to wait for the doom buggy with the side cut down to make the transfer a little easier. Many of the buggies were coming through empty. When "our" car arrived, they stopped the moving walkway, and didn't rush us about making the transfer. They also let us stay on for a second ride, since the transfer was so difficult. We also got to ride Small World twice in a row because there weren't any other wheelchairs waiting.
All told, we did Jungle Cruise, Tiki Room, Haunted Mansion (twice), Small World (twice), Philharmagic (twice), Big Thunder Mt. RR (DD & DGD), got cocoa and cookies (twice), sat at an outdoor table next to Aladdin for quite a while as we decorated ourselves with glow bracelets/necklaces/anklets, etc., watched the fireworks, had a front row seat in Liberty Square for the second parade, and topped off the evening with DD & DGD riding Space Mountain (twice), while I did some pin trading in the gift shop at the exit. Granted, we didn't have any small children with us, we ate "dinner" before we got to the park, and we chose to skip T'was The Night Before Christmas and the show in front of the castle, but we didn't feel rushed or overly crowded at any point during the evening. Perhaps we just managed to be where most of the people weren't throughout the evening. We didn't get the family photo because the lines were too long, and we only saw it snow on Main Street as we were leaving the park, but we had a fabulous time (except for it getting quite a bit colder than we had expected).
We aren't early risers, so it was nice to get to the park at 4pm and be able to walk right onto all of the rides we wanted to. We probably won't come to Disney World again for a few years, and we might try for a different time of year. However, considering that our three days in the parks were during the week before Christmas (MVMCP 12/20, MGM 12/22, & Epcot 12/23), we were very happy with the crowd level. I think it really helped that we avoided each park on its EMH day.