When my parents died, there was a certain protocol we had to follow - procession from the funeral home to the cemetery and such like. I doubt any director would allow you to throw a party in the place - especially if there is another one in the next cubicle.
Do what my family did. Invite the people you want to come to your wake and funeral to a meal afterward in a decent restaurant. It can be a general announcement at the graveside:"Ladies and gentlemen - the funeral for Mr. /Mrs. (name) is completed. The family would like you to join them for a meal at (restaurant), Thank you."
There are going to be tears. People can't stop crying when they are sad or in pain.