Hello Laura,
You are going to love seeing Mickey's Very Merry Christmas Party through the eyes of your son. It's a whole new experience for sure. My husband and I attended the party before we had children and then after and it was so amazing to see my daughter light up in wonder at all of the party decorations, the snow on Main Street, USA, and Holiday Wishes.
During last year's MVMCP, Mickey and Minnie greeted guests at their regular meeting spot,
Town Square Theater, decked out in their holiday outfits. We have not received official information on the meet and greet locations for this year, but as soon as the party map is released online (the
Disney Parks Blog gave us an early preview of the Mickey's Not-So-Scary Halloween Party map this year), you'll be able to confirm the probable meeting location. Sites like the Unofficial Disney Character Hunting Guide and other unofficial sites will post photos of the characters from the party online as early as the next day.
Please let me know if you have any other questions!
Have a Disney day,
Ashley