ADR questions

[MaggieMoo'sMom]

All of my ADRs are for 3 people, but I am thinking of letting DD4 bring her cousin. How hard is it to go from 3 to 4 people on an ADR? I know it would be very hard to go from say 4 to 5, or 8 to 9, but won't there be an extra seat at our table anyway?

 

[Hopefully]

How close is your trip?
In general I would say it will be very hard to actually change the ADR from 3 to 4. They will not simply up your number for you. What they will do is cancel your ADR for 3 and then look for an opening for 4.
I know that makes no sense, but it is the system in place.