help, please?

rough draft of guest list.... 150ish. how do we cut down to 100? i don't want more than 120 people. when i have a list of 150, should i assume that 30+ people will not show up? or do i only invite 100? i don't want to hurt anyone's feelings:

at the cookout last night, my mom said that her old-time friend, trudy, was upset that she wasn't invited to the plank-rohrer wedding. the wedding was in 1983... trudy told her LAST NIGHT. how long has trudy held that grudge? would they have kept in touch if she was invited?

this is ridunkkkkk. someone please make all the decisions for me. thanks.