Awww.... Heather I feel for you! THE most important thing is that you and FI are on the same page. If family not being there is an issue, then maybe you both need to reconsider. If you think you can still make it your special day without them then you should! A word of advice though.... you will NEVER make everyone happy! No matter how hard you try, someone will have something to say. Another thing.... and I'm not trying to burst your bubble, I'm only saying it because I was naive and optimistic and I am paying the price - don't expect that everyone will come. I know you're thinking that you're giving lots of notice so whats the problem right I thought the same thing..... I gave 18 months notice and I have one person that has booked and a bunch that promised they would be there bu are now giving excuses.
So your question was how do we survive, well my very supportive and fantastic FI and of course the ladies on the forum!
IMO, you need to do what will make you and FI happy as a couple.....that's the most important thing.