Ok here goes.

I think your 2 week plan is a good one.
solidarity and unity are a must.
I think Amber’s plan up on the wall is a good one too. Talk about it and then have the plan printed as a backup.
When DH was on deployment up in the NT was when I chose to get Darcy out of our bed. She was already in her big bed so I didn’t have to worry about that, but I just had to be consistent. When she got up, I took her back and sat with her until she was asleep. I showed her how the monitor worked so she knew I could hear her if she spoke. You won’t need a monitor, but show them how you can hear them without them coming in to you. Get DH to sit in their room and call quietly maybe?
I spent many hours over a few weeks sitting next to Darcy. I read books/magazines (I had a stash in her bedside drawer lol), meditated, sang. At first I held her hand, then just sat on the bed, then on the floor then a bit away then at the door.
I second the not taking the baby’s dummy away. Maybe DD because she is old enough to be complicit, but not DS’s - especially if you are going to night wean. I have just recently gotten rid of Darcy’s via the Dummy Fairy and it was uncomplicated and non stressful for all involved.
Do you think they might be good in a bed together? We’re thinking of getting a bunk with a double bottom for Darcy’s room for when Nate is a bit older as they both like to ‘share’.
As I think of more I will get back to you - but I really think what you’ve already got is a great idea.
oooh and Anna has some top ideas too.