I would try it, you won't lose anything by giving it a go. We had a similar situation. Baby in her cot next to our king size bed, husband ended up sleeping in the spare room. When the baby was 12 months, I decided I wasn't going to sleep in the same room anymore. So since that time, she's been sleeping alone, more or less until the first wake up. If that was before 4am, I usually put her back in the cot and left, otherwise I would stay and co-sleep in the big bed until the morning.
She started doing longer stretches of sleep around that time, but that might have coincided with her starting nursery and starting to walk.
She started sleeping through around 14-15 months.
Now at 18 months she sleeps around 9.5 hours in one stretch, alone in the bedroom.
To cut the long story short, I don't regret stopping sleeping in the same room.
We still need our bedroom back though so the next step for us is to move our DD to the other bedroom which was supposed to be hers.
It's a noisier room, so I'm really worried, but we'll see how it goes.
We're doing it next weekend :-D
Good luck - you can at least explain to your daughter that she's going to have her big girl room now, let her decorate it, build it up as something super positive ;)
Hope it goes well 