Hi, Congrats on your gorgeous little boy and welcome to BB!

My DS was in my room for about 3mths when he outgrew his cradle, I started putting him in his cot for day sleeps (as you have done) and eventually he was there all night. I know "they" say not to do it but can you put your DS to sleep in your arms then gently lower him into the cot asleep? I know that might start another habit though.

DD is still in my room and she is almost 7mths old, the plan was once she outgrew her bassinet she would be in her room but its too convienient for her to be in the room so I can feed her if she does wake up.

Oh I just remembered I had been putting DD in her cot in her room during the day a while ago and she wouldn't stay asleep for long if at all, we have now put the cot in our room and she has slept great! Is that an option for you perhaps to make the transition to his room smoother? New bed, familar surroundings.....then familar bed, new surroundings??

HTH