The invitation that does the heavy lifting
In this sequence the invitation earns its keep, because it is the instrument that produces the numbers instead of the guesses. A birthday page with the plan up front and a reply button attached gives you names, companions, and meal notes arriving against the guest list as the week runs — the count that stages three and four hang on.
My Joyfullday's birthday pages do this in both directions: guests see the time, place, and theme, and their yes lands on your list with everything attached. Remind the quiet ones from the same screen, update a line if the venue shifts, and after the day the photos and wishes stay on the page as something the birthday person can actually keep.