Help please! Baby Waking at 2:30-3am and fussy...

Baby K

My LO is a c section baby and she is 3.5 months now. She's tiny and just at 10lbs. She takes between 20-23 oz per day of formula and tends to cluster feed during the earlier part of the day and then then doesn't finish her bottle during her last two feeds. She was sleeping great the last couple weeks - down at 8:30, dream feed by hubs at 10:30-11pm and wakes at 6am. The past three nights she's been waking at 2:30-3am and is either super congested or needs a small feed (about 2-2.5 oz). I took the taking cara babies course and tried the methods but she still wakes. She's in our room in a bassinet. Any suggestions on how we can get her to eat more closer to bed and go back to sleeping through the 7-8 hours we enjoyed? We are planning to transition her to her crib in her nursery this weekend too.