G.B.
Okay, looked back at your previous question to find out how old the baby is.....
You said in February he was 9 months old so that means in May or June he'll be 1 year old. He's too young to be off the bottle right now. His nutrition is coming from taking that bottle. He should be drinking about 30 ounces of formula or breastmilk per day right now. SO he needs his bottle.
He's not supposed to be taking a sippy cup. He's supposed to still be taking a bottle. If you take away his bottle too soon he'll start sucking his thumb or fingers because baby's need to suck. It's their nature. It's ingrained in them to suck because it's how they are supposed to eat.
I'd say you need to just wake up and feed him a bottle. A LOT of kids never sleep through the night all the time until they're almost 2. They want a bottle or they want food. They are growing a LOT and need extra nutrition. So you need to provide it.
You have all summer to work with him using a sippy cup along with giving him a bottle. He's not even 1 yet and he cannot stop taking a bottle. He's hungry during the night, it's what baby's do, they wake up and take a bottle, he needs his nutrition.
When we are asleep our brain is at it's peak, working to fight off illness/disease, and it's growing the body, etc....during sleep our bodies use tons of energy. If he isn't getting enough formula/breast milk he's going to wake up. He's using up all the food in his body in just a little while.
Work on making sure he's getting enough formula/breast milk during the day. When he gets to a plateau growth wise he'll sleep through the night for a little while then he'll start working on something, could even be just fighting off a cold, and he'll start waking up every few hours starving again.