Hi Keira, I agree with Astrid - its really hard to decide on sleeping arrangements until bub is here... I always thought we'd have Natalie in our room, but after two nights of zero sleep while I heard every little noise she made, we moved her. We have shared a room on holiday too and I just find it so hard to sleep while she's there!
It wouldn't be the end of the world if you found you felt a similar way in a one bedroom place - My mum and dad lived in a one-bedda when they had my brother. They would put him in a 'car basket' (you could use a cocoon or port-a-cot or whatever) in the bedroom at the start of the night, then when they went to bed they'd move him into the living room without waking him.
Of course, here's hoping you like sleeping with your baby, that'd be the easiest option! And totally doable, I reckon.