Private Ceremony Etiquette

My FH and I are planning on having a private wedding ceremony with only 30 immediate family members and closest friends. We are then inviting the rest of the guests (about 80) to the cocktail hour and reception immediately afterwards. I'm getting ready to order invitations which will be sent to all guests that are reception only invitations. I was thinking I should include an enclosure card for the private ceremony members which states the time they should arrive. Is this the best way to go about this?? I don't want the other guests to feel excluded, but we are both pretty shy and want our vows to be witnessed by only our closest family. I have seen many examples of reception enclosure cards...but that doesn't seem to make sense in this situation. Any thoughts or examples of private ceremony enclosure cards?? Thanks!