Onlook 2-in-1 Convertible Car Seat

Not who you asked, but we really like the cosco one. It’s cheap ish so not too pricy as an additional seat, and it’s one of the lightest you the market for carrying through the airport. You can also buy a car seat backpack from 3rd party sellers which was really good for the airport of it all.

I uber all the time with my toddler and we use the Cosco Onlook car seat and use a harness to sit it on our travel stroller. It has worked extremely well and its lightweight and easy to install in cars. My toddler just rides in the tethered car seat when we get out of the uber.

Uh no way am I skipping the carseat. We have the lightweight Cosco one and even when traveling by myself with the I haul it, our luggage and my 3 year old. I usually just rent a car wherever we're going and deal with installing it.

We also do the lightweight Cosco seat with a padded carrying backpack that we check. Set it up so the harness height is situated in advance and make sure you know how to safely install it. Depending on your budget and child’s size (under 45 inches and 50 lbs so likely for a 4 year old but it’s expensive to not be able to use a lot) there’s also the WayB Pico which is super light and compact for travel. i would definitely do a stroller for a 4 year old at Disneyland but would rent there through BabyQuip or at the park. I’d also gently encourage you to learn how to install all of your car seats. Kids can accidentally unbuckle them climbing in and you need to understand the install. Most manufacturers usually have videos on YouTube you can look up!

I'm a parent of 4 and we fly a lot - I'd absolutely bring the car seat on the plane. It's safer, and it gives her a comfortable familiar space to rest. We own a lightweight cosco carseat just for the purpose of travel. Also, there is no limit for amount of breast milk allowed. I'd buy a soft sided cooler that fits the carry-on size requirements and put the milk in there with ice packs. You can also bring a diaper bag for free with most airlines (in addition to your personal bag).