How do you dress a baby for sleep?

My 5 month old has been waking up with really cold legs, arms and feet. I recently transitioned him from the Snoo where he was bundled up in a swaddle and I used to put an extra blanket inside. Now, he sleeps in a crib with just a onesie or a pajama. I’m a new mom and I don’t know how to dress a baby who rolls over. Any suggestions? He prefers sleeping on his tummy so swaddles are out. It’s quite warm when I put him to bed but we do leave the A/C on and it usually cools down in the middle of the night.