We took our twins at ten weeks or so. It was an early December trip. The dr said it was fine but do check with yours. The trip was not really any different than being at home with them. Dh always says, "You parent here or you parent there." I think that's a good attitude. We did have a one bedroom at OKW. I remember that dd slept in the laundry room and ds in the huge master ensuite. Our eldest took the pull out.
We had a great time. They mostly slept at the parks and rides were the same at eight weeks as they were at a year and at eighteen months. Rider switch for the biggies, in our arms for others.
Having laundry was a godsend. We had baby supplies delivered by garden grocer. The hotel provides pack and plays. I had extra pillows rigged up to use as baby seats.
The extra clothing for mom and dad on the plane is essential. I did that until they were about three. At about four I got Sprite poured all over me during a flight. That wasn't fun.
I left a 6 week old and a 21 month old to go away for a long weekend with DH. I felt bad for my IL's, because my 6 week only wasn't sleeping through the might've (my mom had the 21 month old). Everyone survived!My mom helped with my baby too, but there's a big difference between getting help with a new baby and leaving the baby to go on vacation. I think it might be difficult/overwhelming to pump enough milk to last the duration of the vacation too. I would highly doubt many people would leave an 8 week old for the purpose of going on vacation. I find it difficult to believe there are people who would even want to do that. At any rate, it didn't sound like an option OP was considering.
Someone upthread talked about being type A Disney planners. We are dvc members and go frequently. I suppose that changes how we look at trips. We enjoy the parks and activities but being at WDW isn't much different than being home. It is home. We don't get any help at home so I'm used to being outnumbered. I'm minimalist with gear too. So as people have said, every situation is different. Op needs to assess their approach to parenting and if this trip could be a lot of fun. I think it could be great. I was just so happy to be there as a mom of three.You parent here or you parent there.
Well, you did it and it was fine, so I can't argue with your experience, but parenting a newborn (or newborn twins) at home for me was ALWAYS easier than going anywhere else. Even grandparents who had a crib, etc. Just the options for diapers, feeding, calming, toys, etc. were so much better at home than going anywhere else.
Also, at home, versus on vacation, you might get a little help every now and then from a grandparent, etc. So if the OP does not bring a helper, it is on two people to cake care of all the children. Even with my 3 kids who aren't babies, it is exhausting to be outnumbered on vacation. Also, at home, the older kids are easier to take care of...they can entertain themselves, feed themselves much easier than in a hotel room.
ETA: Also, at home, I'm not paying for an expensive Disney vacation and not making the most of it. Nor wasting my or DH's vacation time from work.
I don't understand the logic of "You can do this hard task here with better equipment and support OR you can do this hard task with less equipment and support AND you will have to pay thousands of dollars for that"
I have taken a two- year old twins, a kid turning 3, 3 year old twins, and a 4 year old, and a 5 year old. All those ages were "magical" in terms of wanting to meet characters and still believing. And my 10 year old barely remembers the trips when he was 3, 4, and 5 (if really at all, he says some things about the 5 year old trip). I'm not one to advise against waiting for an 18 month old because they won't remember, but really, you have time for your kids to still have fun and believe in magic OP.
We took our daughter when she was 8 weeks old, and our son was 2 years old, and we had a great trip. I checked with her pediatrician beforehand and she was fine with us taking her. I mostly wore her in a carrier around the parks. The part that made me the most nervous was the plane ride, but luckily she slept the whole time.
Good luck with whatever you decide!
But OP also has a 9 and 12 year old that will not want to go the pace of an infant and 18 month old. They will want to go on the more adventurous rides and will need a parent with them for every ride always leaving another parent with the 2 young ones. That is a lot to juggle for a new mom. I feel like there will be guilt and stress trying to please everyone and she will be exhausted. I mean I love Disney and I love bringing young ones there but 2 under 2 AND 2 tweens while 8 weeks postpartum? That is tough.