We have a party of 9 and for the large group ADRs, if someone doesn’t show what happens? What if I know that 2 won’t show to a reservation- can I try to modify it for 7 or will I lose the whole thing?
As long as one person shows up, you are good. however, if you want, you can modify the reservation to free more space for other people.
As @lbellemare said there is no penalty for showing up with less people. If you are not able to modify your ADR I would not worry. Just think- if you get seated at a smaller table, maybe that will free up a table for someone that tries to walk up and get an ADR!
You will have no problem