Flying with 3 babies & a dog alone

Good morning! 1 week from today I will be flying from California to New Orleans, Louisiana with my 4 yr old, 1 yr old, 2 month old, & our little dog. I have traveled extensively alone with 2 and a dog and pregnant but now my 3rd baby is here and this will be our first try at it. So my question is this and I'm just looking for suggestions. I have a double stroller and I can either put the 2 seats on it for my older 2 and wear the baby (dog rides under the stroller) or I can put 1 seat and 1 bassinet for my younger 2 and have my oldest walk. We have 1 layover both going and coming back. During our layovers I have a quick routine of 1st priority is pet relief bc its her only chance to go potty all day for the dog, then bathroom for 4 yr old and self, get food for the kids and get to gate. It's easier to do all of this fast not having my 4 yr old in his own world walking through the airport and just putting him in the stroller. I have a travel bassinet that folds up into a back pack that I can take out if I need a place to set my 2 month old outside of her carrier but obviously this isn't as convenient as just having her in the stroller bassinet. What would you do? 2 seats or 1 seat 1 bassinet and oldest walks?