OP here- Still not sure which way to go with this trip. Was talking to the girls a little bit more and the littlest one was the only one that was a definite yes. The other 2 want to check out Epcot at least. I told the little one that the 2 of us should go together and leave the other 2 girls at home. She was all for that but the other 2 weren't thrilled with the idea. Really, there is not a huge amount of difference money wise between taking 1 or 3. I just keep thinking that there are so many other things that the girls would really love for the same amount of money. I know the littlest would be a great age for DW and she is such an expressive child that it would be a lot of fun. I have been pricing out making it a shorter trip and I'm even considering doing a park day, staying overnight, doing another park day, taking a few days off at the grandparents house then coming back and doing it again. We would miss out on 'the bubble' but would at least be able to hit the 4 parks.