I had 2 daughters in 2 years. I wouldn't change a thing. I am glad they are not in the same class so they have separate friends and activities, but there is a lot they have done together at summer camp and girl scouts. Also, when it comes time to leaving them home alone or letting them fly to Grandma alone, they aren't really 'alone'. They help each other out! But like Creidgirl said, they can truly terrorize each other. They also shared a room until the big one turned 10. Her 10th bday present was getting her own room. Just picking out the paint was a thrill for her. For a while they arranged their beds so they could still see each other in the hall from their beds, but they don't curl up together. Also, when we vacation they keep each other company. They find each other in the pool or share a bed in the hotel room. They sure like having someone else their age around when we are out of town.
Just saw your post to my page, we are in Barre. We got hit pretty good (bad?). My kids are 17,16,14 and 12 so I did 4 in 5 years. I wish I had some great advice, but I would not change the spacing. They really are close and although they fight like cats and dogs. They can be brutal to each other but they are also each others best defenders.
I make up silly rhyming songs and sing them really loud so that I won't scream too much. The kids cringe when I start singing but hey it's better than yelling and we usually end up laughing about the silly rhymes. Hey it works for me. And lots of Diet Coke with Lime.
Take care and good luck with your ice damage and kids!