A.P.
I think it'll be really tough without the carrier. my 2 are a year apart so I know about this situation. We also had the permanent convertible carseat but it just didn't cradle the newborn like the carrier did, plus you have to take the baby out every time. With the carrier, you can leave the baby in the carrier without having to expose them to the cold, waking them up, etc. trust me it'll be much more difficult without it. You can also get it as a combo carrier/stroller, you can have a single or double stroller. Both can hold the carrier, makes it really convienent. good luck, hope it helps