I guess we all have different approaches.

I'd do the exact opposite. I'd put them both down at the scheduled time and know that it's going to take a little while for them to settle. My reasoning is purely that it is going to have to be done at some stage since you have stated that's the only place for them in the long-term.

I have found that if a child is going to take a little time to adjust to a change, then why have two situations of change when one tackles the issue head on.

What are you going to do when others come in October? How are you going to run a day home in a one bedroom apartment?