wording to invite family members/friends only to ceremony with a plus one for the reception?

I don't think there is a polite way to do this. If I were invited to a wedding/reception and FH was only invited to the reception, we wouldn't attend.

I would send a regular invite and maybe print a note to include with the certain ones who will have that option. Also, word of mouth is a good way to explain it.

Have the note say: Please, it would be a blessing to have you at our union. You may, if you wish, bring a guest to the reception at *insert location, date time*. Or something like that.

This is not a traditional route and since your family understands and is willing to be accommodating, I see no issue.

I'm not sure how to best do this. It's kind of rude to invite people with a guest, but only allow the guest to be there for part of it while the person invited is there for the whole thing. I'm just thinking as to what they would do during the ceremony or transportation issues if they only have one vehicle for the two of them. But if your family is okay with this, maybe just verbally letting the people the people that this applies to know. Just give them a call and say "Hey, just wanted to let you know that the invites went out in the mail yesterday! We'd love for you to be there and you can bring a guest to the reception if you'd like, but we'd like to keep the ceremony to strictly family members." I'm in the same boat as Kayla P., though, if I was invited to a wedding/reception and my FH was only invited to the reception, we wouldn't go.

Otherwise, I would just keep the ceremony to your parents, grandparents, and siblings, and then invite everyone to a reception afterwards.

This is very weird to me, what are your oot guests that are not invited to the ceremony, but are to the reception, going to do while the person they came with is at the ceremony?

We actually turned down the state park because they would only allow us to have 50!