We're travelling in May and June with our 1st baby who is due in March, so we don't have any experience yet, but based on advice from other DISers, this is our tenative plan. We're staying onsite for both trips as we figure we'll have to spend more time than normal in the room because of the baby and using Disney transportation would be much easier for us than driving back and forth ourselves. We plan to bring lots of clothes for the baby (and more than usual for us too in case of baby accidents) but of course this is easier for us since we don't have to pack for 2 other kids as well. We're hoping it will reduce our need to do laundry though, and hopefully we'll only have to do it once per trip. Also, when we modified our reservations to include the baby, Disney told us that if we need the refrigerator for medical needs, including storing formula/breastmilk, that we'd get it free, rather than paying the $10/night that they usually charge. Since we haven't done this yet, I can't confirm that it's true, but that's what we were told. Also, since Pop Century isn't open yet and we haven't stayed there, I don't know specifics about the hotel, but I know that we love the All-Stars and would definitely pick 2 rooms there over staying offsite. So if PC is similar at all, we'd choose that over offsite too, if for no other reason than the convenience of being on Disney property. I'm sure others with more knowledge in this area will suggest this too, but look into renting a 1 bedroom DVC unit. That way your older 2 would have their own bedroom and during the day they'd have a space to play too, plus you'd get a washer/dryer and a kitchen. I've never rented points so I don't know how the prices compare, but I'm thinking that you might be able to get one for a little more than 2 rooms at Pop Century.