Camping is my idea of hell on earth. A caravan yes, but not a tent, fuck that. And not with a child and a baby! Don't know what country you're in, but an outside wedding in MARCH? (Is it Spain btw?)
Why the hell could they not have had the thing much closer to home? Why must people get married 100's and 100's of miles from where they live? (Or even 1000's?!) Or is this where they live?
It's very poor form to pull out though, especially as it's so small. You could make up a sixth of the guests! And as someone said already, why did you not say no sooner, knowing what it was going to be?
But yeah, I agree that this is not an enjoyable wedding.... expecting you to bring your own food, sticking you in a tent, expecting you to travel 5 hours.
I think you should suck it up and go, as you have said yes, and the wedding is so close...... But it's your call...
BTW, I hate weddings too. Used to love them, but I hate them now and dread being invited. It was such a relief to not be invited to the wedding of our neighbour's son; it was 8 hours drive away, so we would have had travel costs as well as hotel costs. (As well as money as they were asking people for money, and potentially new outfits.) We assumed we may be invited, as the neighbour kept gabbling on about it, and told us how much we would love 'said town where it's being held!' But we weren't invited, thank God.