We put the cot in the new room for the first couple of nights - is that something you can do?

Also, I gave DD#1 about 4 weeks to be able to go to sleep on her own in the new room/bed. The first week I sat next to her bed holding her hand till she fell asleep (holding or bfing DD#2 if I had to) the second week I stopped holding her hand, the third week I sat on a chair near the door and then gradually moved out before she was asleep.

All the best!
That sounds like a good way to do it actually. Because I was thinking that if I lay next to her every time she'll get used to that and not be able to go to sleep unless i'm holding her. I can imagine though that when I sit on a chair next to the door she'll get out of bed and come over, how did you deal with that part?

One thing that worries me is that is DS's unsettled time. She's used to going to bed with him screaming in the background but I don't know if she'd like being in the same room as him. I'm not comfortable leaving either of them upset by themselves

Unfortunately the cot needs to be taken apart to get out the nursery door, which would be fine if our house wasn't on the market... I have to have the house looking like a display home just in case.

Thanks for all the advice so far (more is welcome!!!)... she did fall asleep in her big bed last night, but only lasted 4 hours before waking up upset, I just ended up putting her back in the cot which was probably a bad move but she just did not want to go back to the big bed.