Late to the party for you! Not sure with changes this year to party about 1st night, and yest typcially Friday parties are more crowded than weekday parties. However, I have been to a sold out
MNSSHP and
MVMCP, been on Halloween night and one a last night sold out MVMCP during the week & have had no problems with a good touring plans. I.E. met the characters I wanted to, rode the rides I wanted to, and the treats free and purchased, saw fireworks, parades, castle shows, and shopped. Select the night that works the best for your trip and have a good plan and be flexible.