See, I have a lot of sympathy with Jean's view. Your DH isn't wrong for wanting you to join in with the full weekend, and the dinner sounds a part of that. You are not wrong with rejecting his solution ot the problem, but that doesn't mean you can't find other solutions that don't involve you missing out.
I'd be weary of the baby at the table thing if you've not done it before with her though, because if she's cranky and doesn't settle in the pram, then you are going to feel the pressure to leave the table anyway to avoid spoiling hte evenings of other diners in the restaurant, and feel the pressure from your DH to stay at the table. (so what you'll actually end up doing is taking it in turns to walk the pram round the gardens in an attempt to get her to sleep)
At least with a sitter you know you have it booked in advance, if your DD doesn't settle in the room, then you can think again about what you do (and still have the pram by the table or you missing out options).
Life doesn't have to stop once you have DCs, and other people don't have to compromise to fit round your child, but the only way you can achieve those is to have childcare. From now on, only book trips away if you can be certain in advance you can have childcare and you include the cost of it in your budget for your trip. If you can't afford the sitter so that you can fully join in with yoru DC safe, then you can't afford the trip.
oh and I've not used sitters the company, but it might be worth checking them out if the hotel don't have a list of CRB checked childminders/nannies/babysitters they can call for you.