Kids at the wedding - parents travelling from abroad?

Wow, for my first post, I'm so grateful for all of your opinions and advice! How exciting! Some very good points you've brought up, I'll try to answer the general questions:

Yes It's a sticky situation. It's funny because I wouldn't consider ours to be a 'destination wedding' per se, as it's not in a resort and we live in France, it's just an hour away from where we live. We're aiming for 120 adults, currently on the list we have 140ish but realize that at least 10% will probably not be able to come. But then there's approximately 25 kids (yes, Irish families). Saying 'no kids' at our wedding is definitely out of the question for us. I guess our hesitation is partly about the cost of the kids (but you're right, kids don't cost as much as adults!) and moreso about the space. The venue can host 150 people (tight) but is ideal for 120. There are some people (adults) that we want to invite but because of 25 children, we have to give up spaces for them! We are definitely going to hire and have a couple of reliable babysitters on-site for the reception and party, as there is a nursery room available where we plan on putting the kids, sitters, games, tv, toys, etc to occupy them while the adults can enjoy themselves.

Also, an international wedding is basically inevitable for us - we both come from mixed nationalities and have family on several continents, we have worked and lived in 5+ countries, so of the 140ish guests on the list, approx 100 will be travelling. That's a big ask, we know, hence why we refuse to say 'no kids' but are struggling with the space and wanting the adults to be able to enjoy themselves to the fullest on this vacation/wedding!

You guys are a fabulous sounding board, it's so hard to plan these things! Thanks everyone!

Also we're going to have a lot of fun trying to get babysitters to deal with children who speak three different languages... French, English, Irish... but the whole wedding is trilingual out of necessity and kids will play with kids no matter what language they speak!

If I was in that position, I would make arrangements for the kids, hire a nanny for the day or have a kids sitter in the bridal suit etc.

The only thing you can really do is have babysitters available on the day. If it is family children who are traveling they can't be left behind as generally children are left with relatives if parents are traveling for a few days and I'd imagine most of the grandparents, aunts, uncles etc will be at the wedding. If you are worried about people enjoying themselves tell the guests that the venue doesn't like small children after a certain hour and babysitters are available. This is not an unusuall thing to tell irish families, most parents will take their children away by 8/9 anyway. That is what happened at ours. During the day for the reception organised babysitters as you were suggesting is your best bet and don't worry about tri-lingual! Irish kids speak English and you will easily find French people who speak English.

Thanks everyone for your advice! We have decided to have the kids for the ceremony but then hire 2-3 babysitters to take the kids for the rest of the evening. This means parents can enjoy themselves, can check on their kids when they want (the room is on-site), the kids will have fun (we will provide games, movies, colouring, etc), and they can eat more kid friendly foods (pizza party, hot dogs, etc) - and all of this means that we don't have to sacrifice 25 adult invites for the 25 children! If the 25 children had to be included in headcount for supper, 25 out of 120 means sacrificing 25 "adult" invites... which was breaking our hearts to have to do. Now, we have a solution that will (hopefully) suit everyone! Thanks for your help guys!