generally, i don't get the 'no kids' rule anyway - and it used to be the case that churches were PUBLIC places, people could only be 'evicted' if they were disturbing the ceremony (which is the ushers job btw), so they can't actually stop anyone turning up - in fact, i've been to a couple of city centre weddings where a tramp has wondered in at the back cos it was dry and warm (ish) compared with outside. as long as they don't disturb, no-one can be 'banned'.
however, personally, the idea of going from kent to scotland for a weekend with a young baby just doesn't appeal. i know it means you'll miss seeing friends, but i'd rather stay home. if you could turn it into a week's holiday, hire a cottage, have some of the friends over/meet in a pub on a different day, i'd consider going. otherwise, i just wouldn't bother.
if dh still wants to go - send him with your blessing, then, when you are able to leave dd, plan your own break for some 'me' time.
fwiw, i do think people who exclude babies, are pretty silly - surely it's obvious that you are therefore excluding at least one parent, which is a fairly hurtful thing to do. it's like saying, 'we only want to be friends under certain circumstances' which isn't really friendship.