How to make the big step easier

Hi ladies!
I am looking for any advice with the big step into moving my 2 year old into his own bedroom!
My husband and I were blessed with our little man in 2013, and from the moment he was born in the hospital, until he was 9 months old he had co slept with us. At 9 months old we decided it was time for him to be in his own cot but still in the same room as my husband and I.
My little dude is now 2, and we just recently moved into a new home, we had our minds set that we were going to put him in his own room, but the moment we got the keys and started moving in and setting up our home, we came up with reasons to not have him in his own room, and so his cot was set right beside our bed! Since moving into the new home he has not been interested in sleeping in his cot, so we upgraded to a single thinking that maybe he just was not comfortable in it anymore, he would fall asleep happily in it, but would end up in our bed throughout the night and now his bed doesn’t even exist to him! We don’t mind co sleeping with him, although he is very much a bed hog! But this is now where we have a problem, I am pregnant with our 2nd son, 20 weeks this Sunday! And I definitely plan on co sleeping again, so now my husband and I have no choice but to move our little man into his own room and have him settled and comfortable before his little brother arrives! So my question is, how do we make this easier for my husband and I to know that he will be ok in his own room? We thought we’d leave the queen spare bed in the room we are moving him into so my husband or I can sleep with him the first few weeks to get him used to the room? This is such a big step for us, but also for him too, as he has always been in the same room as us, so please if anyone has been in this same situation and can help with any advice, it will be much appreciated!
Thank you!