I bought tix for 3 of us for the TTDP. DH may want to join us. Do you think I could add him if I call? I mean, we'll have a table for 3 already w an empty chair, right? I know, that's MY logic, not WDW Dining logic.
Can't hurt to try, but since it probably has a maximum occupancy aside from the # of people per table, I am not sure that your logic will work in this case. I would just call and ask.
I would try to call. I had tickets for 4 for the Illuminations sparkling dessert party at one point. Then one more friend wanted a ticket, so I changed it online, just like changing a regular ADR. This only worked because it was day 180 and I could see a reservation for 5 available. If you do it online there has to be a new reservation for the total number of people available, and your original reservation will be canceled. The downside was that then my credit card was credited the total amount for the 4 and then re-charged the total amount for 5.
Then ANOTHER friend decided she wanted a ticket too. I decided to call this time because I didn't see any availability online - certainly not for a group of 6. The CM on the phone added one to my reservation without a problem. It showed up as an extra 1-person charge on my card.
it doesn't hurt to try both on the phone and that night. I was able to talk to the manager at the party when I was checking in our group in May. We already had 10 people. I asked if there was room for two more. and they were able to accommodate. THEN, I saw an empty table behind us. So I asked if we could add another 3 people and have that table too. And they were able to accommodate that too. This was Memorial Day. So it's not like it wasn't a busy day either. LOL.
It never hurts to ask.