I'm free if your husband can't go. I'm a teacher...I can go alllllll summer
Another vote for SE Asia. I'd also consider an RV trip of national parks (though maybe less fun if you have to backpack the 3 year old), Spain and Portugal, France (a week in Paris and 2 weeks in the countryside). I'd really love to go to Kenya or Tanzania, then onto the Maldives or Seychelles but again, your kids are probably a little young for that.
"Hello babies. Welcome to Earth. It's hot in the summer and cold in the winter. It's round and wet and crowded. On the outside, babies, you've got a hundred years here. There's only one rule that I know of, babies-"God damn it, you've got to be kind.”