I'm not sure if this fits in the etiquette section, but I definitely feel like it should.
I'm getting married in September 2012, and my FMIL is really excited about the entire event. FH and I asked if we can hold the ceremony and reception at my FMIL's house in Southern CA to minimize the traveling for my fiancee's family. What we didn't realize was FMIL's side of the guest list will be 100+. Since this was already so big, we haven't asked my fiancee's dad, and my parents have opted to not invite anyone since they're traveling from NY.
By the shear logistics of having a backyard wedding was adding up too quickly for a guest list of that size, we had asked FMIL to take a hard look at the guest list and trim it down to 60. Unfortunately, she said that it's not possible to trim down, and the most would be 75, which excludes our friends.
At this point, my fiancee and I decided to just change venue from FMIL house to Northern CA to try to absolve her from needing to invite so many people. We would have a more intimate ceremony and reception of just the parents and some close friends.
Long story short, FMIL is has told us she's OK with the change in venue, however, FMIL's step sister and sister-in-law have also offered to throw me a shower, but they are no longer invited given this change. Given the circumstances, there probably won't be a shower, which I am OK with. But, how do I break this news nicely to those who have offered to help out so far, being that these folks are largely FMIL's friends and family or is this really FMIL's duty to break the news for getting over excited?