I've coslept with both bubs & extended breastfed for 2.5 years with my first.
I'll talk about my 3yo as I can paint you a better picture ☺
My best option for getting sleep was to sidecar her cot. I took off one side and put it right up against our bed. Although it was easier to leave her in our bed, I personally didn't do this until she was rolling over. I bf her lying down & when she was asleep I'd slide her over into her bed away from me & she was fine with that. She only woke twice a night up until she was 2yo.
When she was 2 I was able to just offer her a sip of water from her sippy instead of BF.
And when I eventually stopped BF at 2.5 she was only nursed once a day which was at night before bed. She was old enough that she understood when I told her that my 'mumums' were hurting and we can just snuggle to sleep. There were a few tears but she was fine.
Even after completely stopping nursing she would wake twice a night and need to be reassured. Even once she was in her own room as we prepared for her brothers arrival.
But she is 3 now and sleeps right through. Through anything!
She never had to CIO, and she's a very well adjusted, confident little girl ☺
I can't answer if the cosleeping made her more needy at night or if it was just her. My friends bubs were bottlefed and slept through in the own rooms by 8months. But their personality types are very different to my girls.